 United States Court of Appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT



Argued July 12, 2019               Decided October 11, 2019

                        No. 19-5142

                 DONALD J. TRUMP, ET AL.,
                      APPELLANTS

                             v.

  MAZARS USA, LLP AND COMMITTEE ON OVERSIGHT AND
    REFORM OF THE U.S. HOUSE OF REPRESENTATIVES,
                     APPELLEES


        Appeal from the United States District Court
                for the District of Columbia
                    (No. 1:19-cv-01136)


    William S. Consovoy argued the cause for appellants. With
him on the briefs were Cameron T. Norris and Stefan C.
Passantino.

    Duane Morley Cox, pro se, filed the brief for amicus
curiae Duane Morley Cox in support of appellants.

    Douglas N. Letter, General Counsel, U.S. House of
Representatives, argued the cause for appellee Committee on
Oversight and Reform of the U.S. House of Representatives.
With him on the briefs were Todd B. Tatelman, Deputy General
Counsel, Megan Barbero and Josephine Morse, Associate
                              2
General Counsel, and Brooks M. Hanner, Assistant General
Counsel.

    Elizabeth B. Wydra, Brianne J. Gorod, and Ashwin P.
Phatak were on the brief for amicus curiae Constitutional
Accountability Center in support of intervenor-defendant-
appellee Committee on Oversight and Reform of the U.S.
House of Representatives.

    Hashim M. Mooppan, Deputy Assistant Attorney General,
U.S. Department of Justice, and Mark R. Freeman, Scott R.
McIntosh, and Gerard Sinzdak, Attorneys, were on the brief as
amicus curiae The United States.

    Before: TATEL, MILLETT and RAO, Circuit Judges.

    Opinion for the Court filed by Circuit Judge TATEL.

    Dissenting opinion filed by Circuit Judge RAO.

     TATEL, Circuit Judge: On April 15, 2019, the House
Committee on Oversight and Reform issued a subpoena to the
accounting firm Mazars USA, LLP for records related to work
performed for President Trump and several of his business
entities both before and after he took office. According to the
Committee, the documents will inform its investigation into
whether Congress should amend or supplement current ethics-
in-government laws. For his part, the President contends that
the Committee’s investigation into his financial records serves
no legitimate legislative purpose, and he has sued to prevent
Mazars from complying with the subpoena. The district court
granted summary judgment in favor of the Committee, and we
affirm. Contrary to the President’s arguments, the Committee
possesses authority under both the House Rules and the
Constitution to issue the subpoena, and Mazars must comply.
                                3
                                I.
     Shortly after the 116th Congress convened on January 3,
2019, the new U.S. House of Representatives debated and
adopted a set of rules to govern its proceedings. See H.R.
Res. 6, 116th Cong. (2019). Like previous Congresses, the
116th established an oversight committee, the Committee on
Oversight and Reform, which it charged with “review[ing] and
study[ing] on a continuing basis the operation of Government
activities at all levels” and which it permitted to “conduct
investigations” “at any time . . . of any matter,” “without regard
to” other standing committees’ jurisdictions. Rules of the
House of Representatives, 116th Cong., Rule X, cls. 3(i),
4(c)(2) (2019) (“House Rules”); see also id., cl. 1(n)
(establishing the Committee on Oversight and Reform). To
“carry[] out . . . [these] functions and duties,” the Oversight
Committee may “require, by subpoena or otherwise . . . the
production of such . . . documents as it considers necessary.”
House Rule XI, cl. 2(m).

    This case concerns one such subpoena. Issued on April 15
by the chairman of the House Committee on Oversight and
Reform, Representative Elijah Cummings, to President
Trump’s accounting firm, the subpoena requests financial
documents concerning the President and his companies
covering years both before and during his presidency.

     In order to explain the impetus behind the subpoena, we
must go back to the Ethics in Government Act of 1978. Enacted
in the wake of the Watergate scandal, that statute requires many
aspiring and current government officials, including
presidential candidates and sitting Presidents, to file financial
disclosure reports at various times during their candidacies and
incumbencies. See 5 U.S.C. app. 4 § 101(a), (c), (d), (f)
(requiring “a candidate . . . for nomination or election to the
office of President” and “the President” to “file a report
                                 4
containing the information described” in section 102 of the
Act). In their initial reports, presidential candidates and new
Presidents must provide information concerning their income,
assets, liabilities, and employers. See id. § 102(b) (requiring
“[e]ach report filed pursuant to subsections (a), (b), and (c) of
section 101” to contain such information). Once in office,
sitting Presidents must file annual reports disclosing that same
information plus details about any covered gifts, real estate and
securities transactions, and blind trusts. See id. § 102(a)
(requiring “[e]ach report filed pursuant to section 101(d) and
(e)” to contain such information). Presidential candidates
submit their reports to the Federal Election Commission, see
id. § 103(e), while incumbent Presidents file with the Office of
Government Ethics, an “executive agency” tasked with
“interpreting rules and regulations . . . governing . . . the filing
of financial statements,” id. §§ 103(b), 401(a), 402(b)(3),
402(b)(6).

     Last year, the Office of Government Ethics announced that
it had identified an error in one of the several reports that
President Trump had filed since he became a presidential
candidate in 2015. Specifically, by letter dated May 16, 2018,
the Acting Director of the Office of Government Ethics advised
the Deputy Attorney General that, “based on the information
provided” in President Trump’s 2018 financial disclosure
report (covering calendar year 2017), he had determined that
the President’s 2017 financial disclosure (covering calendar
year 2016) omitted “a reportable liability under the Ethics in
Government Act,” namely, “a payment made by Mr. Michael
Cohen,” President Trump’s former personal lawyer, “to a third
party.” Letter from David J. Apol, Acting Director, Office of
Government Ethics, to Rod J. Rosenstein, Deputy Attorney
General, Department of Justice 1 (May 16, 2018) (“Apol
Letter”). Because President Trump’s 2018 filing disclosed that
in 2017 the President had reimbursed Cohen for the 2016
                              5
payment, the Acting Director concluded that “the payment
made by Mr. Cohen [was] required to be reported as a liability”
before it was reimbursed. Id. at 1; see also OGE Form 278e,
2017 Annual Report for Donald J. Trump, Part 8 n.3 (May 15,
2018),       https://oge.app.box.com/v/Trump2018Annual278
(disclosing that “Mr. Trump fully reimbursed Mr. Cohen in
2017”).

     Several months later, then-Ranking Member Cummings
wrote to White House Counsel seeking documents related to
President Trump’s payments to Cohen. See Letter from Elijah
E. Cummings, Ranking Member, House Committee on
Oversight and Reform, to Donald F. McGahn II, Counsel to the
President, The White House, and George A. Sorial, Executive
Vice President of the Trump Organization 4–5 (Sept. 12, 2018).
That letter remained unanswered as of January 2019, when
Representative Cummings, who in the intervening months had
become Chairman Cummings, reiterated his request in a
second letter. See Letter from Elijah E. Cummings, Chairman,
House Committee on Oversight and Reform, to Pat Cipollone,
Counsel to the President, The White House 1–2 (Jan. 8, 2019).
Chairman Cummings also wrote to the new Director of the
Office of Government Ethics, asking him, too, for “documents
related to President Donald Trump’s reporting of debts and
payments to his personal attorney, Michael Cohen.” Letter
from Elijah E. Cummings, Chairman, House Committee on
Oversight and Reform, to Emory A. Rounds III, Director,
Office of Government Ethics 1 (Jan. 22, 2019).

    In February, White House Counsel responded that the
President would consider permitting the Committee to review,
on a limited basis, a subset of the requested documents, but
Chairman Cummings rejected this proposal as inadequate. See
Letter from Elijah E. Cummings, Chairman, House Committee
on Oversight and Reform, to Pat Cipollone, Counsel to the
                                6
President, The White House 1 (Feb. 15, 2019) (“Cummings
Feb. 15 Letter”) (stating that the President’s offer to “consider
providing Committee staff with the ability to review limited
portions of two of the six categories of documents in camera”
would “not obviate the need . . . to fully comply” (internal
quotation marks omitted)). Citing the Oversight Committee’s
status as “the authorizing Committee for the Office of
Government Ethics,” the President’s statutory obligation to
“file . . . public financial disclosure report[s],” and Congress’s
“plenary authority to legislate and conduct oversight regarding
compliance with ethics laws and regulations,” Chairman
Cummings urged the White House “to provide documents
relevant to the Committee’s investigation of these matters.” Id.
at 7–8. “These documents will help the Committee determine,”
he explained, “why the President failed to report . . . payments
and whether reforms are necessary to address deficiencies with
current laws, rules, and regulations.” Id. at 9.

     Two weeks later, Michael Cohen appeared at a hearing
before the Oversight Committee. See Hearing with Michael
Cohen, Former Attorney to President Donald Trump: Hearing
Before the House Committee on Oversight and Reform, 116th
Cong. (Feb. 27, 2019). He testified that he believed, based on
his experience working for President Trump, that the President
had “inflated his total assets when it served his purposes” in
some situations and had “deflated his assets” in others. Id. at
13 (testimony of Michael D. Cohen). Several Committee
Members questioned Cohen’s credibility; he had, after all,
recently pleaded guilty to various crimes, including lying to
Congress. See, e.g., id. at 7 (statement of Ranking Member Jim
Jordan) (“This might be the first time someone convicted of
lying to Congress has appeared again so quickly in front of
Congress.”); id. at 57 (statement of Rep. Michael Cloud)
(asking Cohen to “state what you’ve been convicted of”).
Seeking to support his testimony, Cohen produced to the
                                 7
Committee several accounting documents, all of which
predated Mr. Trump’s presidency. Two of these documents—
2011 and 2012 “Statements of Financial Condition” for Donald
J. Trump—were prepared by Mazars. See “Donald J. Trump
Statement of Financial Condition” dated June 30, 2011;
“Donald J. Trump Statement of Financial Condition” dated
June 30, 2012.

     Chairman Cummings next wrote to Mazars. In a March
2019 letter, he explained that the statements of financial
condition prepared by the firm and supplied by Cohen had
“raise[d] questions about the President’s representations of his
financial affairs,” “particularly [his] debts,” “on these forms
and on other disclosures.” Letter from Elijah E. Cummings,
Chairman, House Committee on Oversight and Reform, to
Victor Wahba, Chairman and Chief Executive Officer, Mazars
USA, LLP 1 (Mar. 20, 2019) (“Cummings Mar. 20 Letter”).
Chairman Cummings highlighted several “specific concerns,”
including: (1) that “[t]he 2012 Statement of Financial
Condition prepared by [Mazars]” intentionally omitted over
$50 million in assets and $75 million in liabilities that “then-
Candidate Trump” later disclosed on his “first publicly filed
financial disclosure made . . . in 2015,” (2) that read together,
the 2012 statement of financial condition and 2015 financial
disclosure indicated that Deutsche Bank had reduced the
interest rate it was charging on a $125 million loan to then-
Candidate Trump, potentially saving him “about $625,000”
each year, and (3) that “both the 2011 and 2012 financial
statements” noted that, before becoming a presidential
candidate, Mr. Trump “ha[d] pledged” almost $20 million to a
“former partner in the Trump World Tower at United Nations
Plaza,” who, “[a]ccording to contemporaneous reports,” was
possibly “the Korean conglomerate Daewoo” or a “German
financial institution.” Id. at 2–3. “To assist [its] review of these
issues,” the Committee requested several categories of
                               8
documents relating to President Trump’s accounts going back
to January 2009. Id. at 4.

     Mazars responded that it could not provide the requested
documents voluntarily. See Letter from Jerry D. Bernstein,
Partner, Blank Rome LLP, to Elijah E. Cummings, Chairman,
House Committee on Oversight and Reform 1 (Mar. 27, 2019).
So, on April 12, Chairman Cummings sent a memorandum to
his fellow committee members explaining his intention to
issue, pursuant to the Committee’s authority under House Rule
X to “investigate ‘any matter at any time,’” a subpoena to
Mazars. Memorandum from Chairman Elijah E. Cummings to
Members of the Committee on Oversight and Reform 3
(Apr. 12, 2019) (“Cummings Memo”). The Chairman
identified four subject matters that, in his view, “[t]he
Committee has full authority to investigate”: (1) “whether the
President may have engaged in illegal conduct before and
during his tenure in office,” (2) “whether [the President] has
undisclosed conflicts of interest that may impair his ability to
make impartial policy decisions,” (3) “whether [the President]
is complying with the Emoluments Clauses of the
Constitution,” and (4) “whether [the President] has accurately
reported his finances to the Office of Government Ethics and
other federal entities.” Id. at 4. “The Committee’s interest in
these matters,” he stated, “informs its review of multiple laws
and legislative proposals under [its] jurisdiction.” Id.

     The subpoena issued three days later. It requested, “[w]ith
respect to Donald J. Trump” and several of his affiliated
businesses—including the Trump Organization, the Trump
Corporation, and the Trump Old Post Office LLC—“[a]ll
statements of financial condition, annual statements, periodic
financial reports, and independent auditors’ reports prepared,
compiled, reviewed, or audited by Mazars . . . or its
predecessor.” Subpoena to Mazars USA, LLP, Apr. 15, 2019
                               9
(“Subpoena”). Furthermore, with respect to Mazars’s
“preparation, compilation, review, or auditing” of those
documents, the subpoena requested all related “engagement
agreements or contracts” “[w]ithout regard to time”; “[a]ll
underlying, supporting, or source documents and records . . . or
any summaries of such documents”; and all related
“memoranda, notes, and communications,” including
“communications related to potential concerns that . . .
information . . . provided by Donald J. Trump or . . . the Trump
Organization[] [was] incomplete, inaccurate, or otherwise
unsatisfactory.” Id. Narrowed somewhat from the Chairman’s
initial request to Mazars, the subpoena sought documents from
“calendar years 2011 through 2018” “[u]nless otherwise
noted.” Id. The subpoena instructed Mazars to comply by
April 29.

    Before that date arrived, however, President Trump and
several of his business entities (collectively, the “Trump
Plaintiffs”) filed this lawsuit seeking a declaratory judgment
invalidating the subpoena and a permanent injunction
prohibiting its enforcement. See Complaint at 13, Trump v.
Committee on Oversight & Reform of U.S. House of
Representatives, 380 F. Supp. 3d 76 (D.D.C. 2019) (No.
19-cv-01136) (“Complaint”). The Trump Plaintiffs also moved
for a preliminary injunction, and while that motion was
pending, the Committee agreed to defer Mazars’s deadline to
comply with the subpoena.

      The district court worked quickly to provide the parties
with an answer. Following the Supreme Court’s direction to
“give[] the most expeditious treatment” to suits seeking to
enjoin congressional subpoenas, Eastland v. U.S. Servicemen’s
Fund, 421 U.S. 491, 511 n.17 (1975), the court “consolidate[d]
[its] hearing on the preliminary injunction” with a resolution of
the merits by “treat[ing] the parties’ briefing”—which raised
                               10
no disputes of material fact—“as cross-motions for summary
judgment,” Trump, 380 F. Supp. 3d at 88, 90; see also Fed. R.
Civ. P. 65(a)(2) (permitting the court, “[b]efore or after
beginning the hearing on a motion for a preliminary
injunction,” to “advance the trial on the merits and consolidate
it with the hearing”). Then, after explaining that its “analysis
must be highly deferential to the legislative branch,” Trump,
380 F. Supp. 3d at 91, the court concluded that each of the four
investigative topics set forth in Chairman Cummings’s
April 12 memorandum represents “a subject ‘on which
legislation could be had,’” id. at 94 (quoting McGrain v.
Daugherty, 273 U.S. 135, 177 (1927)). The court thus granted
summary judgment in favor of the Oversight Committee. See
id. at 105.

     The Trump Plaintiffs now appeal, challenging the district
court’s grant of summary judgment to the Committee (though
not its decision to treat the briefs as cross-motions for summary
judgment). By agreement of the parties, Mazars need not
comply with the subpoena during the pendency of this
expedited appeal. See Oral Arg. Tr. 129. After oral argument,
and at the court’s invitation, the Department of Justice filed an
amicus brief, and the Trump Plaintiffs and Committee
responded. Our review is de novo. See Teva Pharmaceuticals
USA, Inc. v. Food & Drug Administration, 441 F.3d 1, 3 (D.C.
Cir. 2006) (reviewing de novo “the district court’s legal
determination” made after “consolidat[ing] [a] motion for a
preliminary injunction with a final decision on the merits”).
                               11
                               II.
     This is hardly the first subpoena Congress has issued—
legislative subpoenas are older than our country itself—and the
parties draw upon the historical record to support their claims.
Accordingly, before digging into the details of this case, we
think it necessary to place the challenged subpoena in historical
context.

     The story of legislative subpoenas extends all the way back
to the “emergence of [the English] Parliament,” when that
body, as part of its campaign to “challenge the absolute power
of the monarch,” asserted “plenary authority” to hold offending
parties in contempt. Watkins v. United States, 354 U.S. 178,
188 (1957). Beginning in the late seventeenth century,
Parliament armed “a host of committees” with the “powers to
send for persons and papers” in aid of their
“investigat[ions] . . . [into] the operations of government”—
from “the conduct of the war in Ireland” to “[t]he unwarranted
proclamation of martial law . . . by a commissioner of the East
India Company” to “the State of the Gaols of [the] Kingdom.”
James M. Landis, Constitutional Limitations on the
Congressional Power of Investigation, 40 Harv. L. Rev. 153,
162–63 (1926). Across the Atlantic, too, “[t]he privileges and
powers of the [House of] Commons were naturally assumed to
be an incident of the representative assemblies of the Thirteen
Colonies.” Id. at 165.

     After the Revolutionary War and the Constitutional
Convention, the U.S. Congress wasted little time in asserting
its power to use compulsory process to investigate matters of
national—and potentially legislative—importance. The House
of Representatives opened the first such investigation in 1792,
when it passed a resolution appointing a committee “to inquire
into the causes of the failure of the late expedition under Major
General St. Clair,” whose troops had recently suffered an
                                12
embarrassing defeat in the Northwest Territory, and
“empowered” that committee “to call for such persons, papers,
and records, as may be necessary to assist [its] inquiries.”
3 Annals of Congress 493 (1792); see also George C. Chalou,
General St. Clair’s Defeat, 1792–93, in 1 Congress
Investigates: A Critical and Documentary History 1, 2 (Roger
A. Bruns et al. eds., rev. ed. 2011). More investigatory
committees, similarly empowered to issue subpoenas,
followed. For example, in 1814, the House directed an inquiry
“into the causes of the success of the enemy”—that is, the
British—“in his late enterprises” in burning the Capitol, 28
Annals of Congress 310 (1814), and, in 1859, the Senate
established a select committee to “inquire into the facts
attending” John Brown’s raid on Harpers Ferry and to “report
whether . . . and what legislation may . . . be necessary . . . for
the future preservation of the peace,” Cong. Globe, 36th Cong.,
1st Sess. 141 (1859).

     But not until 1880 did “the first case reach[] [the Supreme]
Court to challenge the use of compulsory process as a
legislative device.” Watkins, 354 U.S. at 193. In that case,
Kilbourn v. Thompson, 103 U.S. 168 (1881), the Court held
that the House had exceeded its investigatory authority by
opening an inquiry into the bankruptcy proceedings of a firm
into which the United States had invested money. The Court
explained that Congress’s sole route to a remedy in that
bankruptcy proceeding, like that of all other dissatisfied
creditors, was “by a resort to a court of justice.” Id. at 193.
Accordingly, because under those circumstances the House’s
investigation “could result in no valid legislation,” id. at 195,
the Court concluded that the House had impermissibly
“assumed a power which could only be properly exercised by
another branch of the government,” id. at 192.
                               13
     If Kilbourn created any doubt about Congress’s power to
conduct legislative investigations, the Supreme Court dispelled
that cloud in a pair of cases arising out of alleged corruption in
the administration of President Warren G. Harding. In the first,
McGrain v. Daugherty, the Court considered a subpoena issued
to the brother of then-Attorney General Harry Daugherty for
bank records relevant to the Senate’s investigation into the
Department of Justice. Concluding that the subpoena was valid,
the Court explained that Congress’s “power of inquiry . . . is an
essential and appropriate auxiliary to the legislative function,”
as “[a] legislative body cannot legislate wisely or effectively in
the absence of information respecting the conditions which the
legislation is intended to affect or change.” 273 U.S. at 174–
75. It mattered not that the Senate’s authorizing resolution
lacked an “avow[al] that legislative action was had in view”
because, said the Court, “the subject to be investigated was . . .
[p]lainly [a] subject . . . on which legislation could be had” and
such legislation “would be materially aided by the information
which the investigation was calculated to elicit.” Id. at 176–77
(internal quotation marks omitted). That was enough. Although
“[a]n express avowal” of the Senate’s legislative objective
“would have been better,” the Court admonished that “the
presumption should be indulged that [legislation] was the real
object.” Id. at 178.

     Two years later, in Sinclair v. United States, 279 U.S. 263
(1929), the Court echoed many of the same refrains. In this
second case, Harry Sinclair, the president of an oil company,
appealed his conviction for refusing to answer a Senate
committee’s questions regarding his company’s allegedly
fraudulent lease on federal oil reserves at Teapot Dome in
Wyoming. The Court, acknowledging individuals’ “right to be
exempt from all unauthorized, arbitrary or unreasonable
inquiries and disclosures in respect of their personal and private
affairs,” id. at 292, nonetheless explained that because “[i]t was
                                14
a matter of concern to the United States,” “the transaction
purporting to lease to [Sinclair’s company] the lands within the
reserve cannot be said to be merely or principally . . . personal,”
id. at 294. The Court also dismissed the suggestion that the
Senate was impermissibly conducting a criminal investigation.
“It may be conceded that Congress is without authority to
compel disclosures for the purpose of aiding the prosecution of
pending suits,” explained the Court, “but the authority of that
body, directly or through its committees, to require pertinent
disclosures in aid of its own constitutional power is not
abridged because the information sought to be elicited may also
be of use in such suits.” Id. at 295.

     The Court returned to the question of Congress’s
investigative authority during the Cold War, as “investigations
into the threat of subversion of the United States Government”
began to raise “novel questions [about] the appropriate limits
of congressional inquiry” “into the lives and affairs of private
citizens.” Watkins, 354 U.S. at 195. At first, the Court avoided
these thorny First Amendment issues by resolving cases on
other grounds. In United States v. Rumely, the Court overturned
a defendant’s contempt-of-Congress conviction for refusing to
answer a congressional committee’s request for “the names of
those who made bulk purchases” of “books of a particular
political tendentiousness.” 345 U.S. 41, 42 (1953). Rather than
reach the “[g]rave” First Amendment question posed by such
an inquiry, the Court interpreted the House’s authorizing
resolution, which instructed the committee to study “lobbying
activities,” as failing to permit an investigation into the sale of
books. Id. at 45, 48. And a few years later, in Watkins v. United
States, the Court overturned another contempt conviction, this
time holding that the defendant, a labor organizer who had
refused “to testify about persons who may in the past have been
Communist Party members,” 354 U.S. at 185, had received
insufficient notice of “the ‘question under inquiry’” at his
                                15
congressional hearing, id. at 214 (quoting 2 U.S.C. § 192). In
that case, the Court took the opportunity to emphasize that
although “there is no congressional power to expose for the
sake of exposure,” courts should avoid “testing the motives of
committee members for this purpose.” Id. at 200. Rather, the
crucial inquiry is whether a “legislative purpose is being
served.” Id.

     The Court soon reached the First Amendment issue it had
been avoiding. In Barenblatt v. United States, the Court
considered the case of a teacher convicted of criminal contempt
for refusing, when testifying before a Subcommittee of the
House Committee on Un-American Activities, to answer
questions about his “past or present membership in the
Communist Party.” 360 U.S. 109, 126 (1959). Unlike the
Watkins defendant, the Barenblatt defendant had been
“sufficiently apprised of the topic under inquiry” by “other
sources of . . . information,” such as the Subcommittee
“Chairman’s statement as to why he had been called” to testify
and the questions posed by the Subcommittee to previous
witnesses. Id. at 124–25 (internal quotation marks omitted).
Proceeding, then, to the “precise constitutional issue”—
namely, “whether the Subcommittee’s inquiry . . . transgressed
the provisions of the First Amendment”—the Court explained
that although “Congress may not constitutionally require an
individual to disclose his . . . private affairs except in relation
to” “a valid legislative purpose,” such a purpose was present in
that case. Id. at 127. Congress’s “wide power to legislate in the
field of Communist activity . . . and to conduct appropriate
investigations in aid thereof[] is hardly debatable,” said the
Court, and “[s]o long as Congress acts in pursuance of its
constitutional power, the Judiciary lacks authority to intervene
on the basis of the motives which spurred the exercise of that
power.” Id. at 127, 132. Thus, given “the governmental
interests . . . at stake,” the Court concluded that “the First
                               16
Amendment [had] not been offended” and affirmed the
defendant’s conviction. Id. at 134.

     Presidents, too, have often been the subjects of Congress’s
legislative investigations, though fewer of these have required
judicial intervention. Historical examples stretch far back in
time and broadly across subject matters. In 1832, for example,
the House vested a select committee with subpoena power “to
inquire whether an attempt was made by the late Secretary of
War . . . [to] fraudulently [award] . . . a contract for supplying
rations” to Native Americans and to “further . . . inquire
whether the President . . . had any knowledge of such attempted
fraud, and whether he disapproved or approved of the same.”
H.R. Rep. No. 22-502, at 1 (1832) (internal quotation marks
omitted). Shortly after World War II, Congress’s Pearl Harbor
Committee published a joint report exonerating the President
of “charges” that he had “tricked, provoked, incited, cajoled, or
coerced Japan into attacking this Nation.” S. Doc. No. 79-244,
at xiii, 251 (1946). In 1987, the House established a committee
to investigate the Iran-Contra Affair, including “the role of the
President.” H.R. Rep. No. 100-433, at 21 (1987). During that
investigation, President Reagan declined to assert executive
privilege, going so far as to furnish “relevant excerpts of his
personal diaries” to Congress. Morton Rosenberg,
Congressional Research Service, RL 30319, Presidential
Claims of Executive Privilege: History, Law, Practice and
Recent Developments 14 (Aug. 21, 2008) (internal quotation
marks omitted). And in the 1990s, first the House and Senate
Banking Committees and then a Senate special committee
investigated President and Mrs. Clinton’s involvement in the
Whitewater land deal and related matters. See Douglas L.
Kriner & Eric Schickler, Investigating the President 56–62
(2016) (describing the “three-year congressional investigation
of Whitewater”); see also S. Res. 120, 104th Cong. (1995)
(establishing the Senate Special Committee to Investigate
                                17
Whitewater Development Corporation and Related Matters).
Thanks to a last-minute compromise between the White House
and the Senate, the courts were kept out of a dispute over
whether the special committee could subpoena meeting notes
taken by President Clinton’s former lawyer. See Louis Fisher,
Congressional Research Service, RL 31836, Congressional
Investigations: Subpoenas and Contempt Power 16–18
(Apr. 2, 2003).

     Of all the historical examples, perhaps the most high-
profile congressional investigation into a President—and the
only one we have found that produced an appellate-level
judicial opinion—was Congress’s investigation into President
Nixon. The Senate created the Senate Select Committee on
Presidential Campaign Activities, better known as the Senate
Watergate Committee, to investigate “illegal, improper, or
unethical activities engaged in by any persons” involved in a
campaign “conducted by . . . any person seeking nomination or
election . . . for the office of the President of the United States”
during the “Presidential election of 1972.” S. Res. 60, 119
Cong. Rec. 3255, 93rd Cong. § 1(a) (1973) (emphasis added).
In Senate Select Committee on Presidential Campaign
Activities v. Nixon, our court was asked to decide whether
President Nixon had “a legal duty to comply with” a subpoena
issued by the Senate Watergate Committee for “taped
recordings of five conversations . . . discussing alleged
criminal acts.” 498 F.2d 725, 726–27 (D.C. Cir. 1974) (en
banc). President Nixon, apparently taking no issue with the
general power of congressional committees to subpoena sitting
Presidents, instead asserted executive privilege over the
individual tapes requested, arguing that they “[could] []not be
made public consistent with the confidentiality essential to the
functioning of the Office of the President.” Id. at 727 (internal
quotation marks omitted). In the end, we agreed with the
President: although the “presumptive[] privilege[]” protecting
                               18
“presidential conversations” could “be overcome . . . by an
appropriate showing of public need,” id. at 730 (internal
quotation marks omitted), we explained, the Committee had
failed to make such a showing “in the peculiar circumstances
of [that] case,” id. at 733. But even though the Senate
Watergate Committee ultimately lost, Senate Select Committee
strongly implies that Presidents enjoy no blanket immunity
from congressional subpoenas. After all, if such immunity
exists, it would have been wholly unnecessary for the court to
explore the subpoena’s particulars and to weigh “the public
interest [in] favor[] [of] confidentiality” against a “showing of
need by another institution of government”—that is, Congress.
Id. at 730.

     All told, from Congress’s centuries-long experience
issuing legislative subpoenas, and the courts’ (somewhat less
frequent) experience reviewing them, a few principles
emerge—principles that control our resolution of this case.

      As an initial matter, “whether [a] committee [is]
authorized [to] exact the information” it has subpoenaed “must
first be settled before . . . consider[ing] whether Congress had
the [constitutional] power to confer upon the committee the
authority which it claim[s].” Rumely, 345 U.S. at 42–43. In
other words, it matters not whether the Constitution would give
Congress authority to issue a subpoena if Congress has given
the issuing committee no such authority.

    That said, once a committee has been delegated “[t]he
power of the Congress to conduct investigations,” that
constitutional authority “is broad.” Watkins, 354 U.S. at 187;
accord Eastland, 421 U.S. at 504 n.15 (“[T]he power to
investigate is necessarily broad.”); Barenblatt, 360 U.S. at 111
(describing Congress’s investigative power as “broad”);
Quinn v. United States, 349 U.S. 155, 160 (1955) (same);
                              19
McGrain, 273 U.S. at 173–74 (same). “It encompasses
inquiries concerning the administration of existing laws as well
as proposed or possibly needed statutes,” “[i]t includes surveys
of defects in our social, economic or political system for the
purpose of enabling the Congress to remedy them,” and “[i]t
comprehends probes into departments of the Federal
Government to expose corruption, inefficiency or waste.”
Watkins, 354 U.S. at 187. In short, “[a] legislative inquiry may
be as broad, as searching, and as exhaustive as is necessary to
make effective the constitutional powers of Congress.”
Townsend v. United States, 95 F.2d 352, 361 (D.C. Cir. 1938).
Expansive as it is, however, Congress’s subpoena power is
subject to several key constraints.

     First, because “the power of Congress . . . to investigate”
is “co-extensive with [its] power to legislate,” Quinn, 349 U.S.
at 160, Congress may in exercising its investigative power
neither usurp the other branches’ constitutionally designated
functions nor violate individuals’ constitutionally protected
rights. Congress may not conduct itself as “a law enforcement
or trial agency,” as “[t]hese are functions of the executive and
judicial departments.” Watkins, 354 U.S. at 187. And Congress
lacks any “general power to expose where the predominant
result can only be an invasion of the private rights of
individuals.” Id. at 200.

     Next, precisely because “[t]he scope of [Congress’s]
power of inquiry . . . is as penetrating and far-reaching as the
potential power to enact and appropriate under the
Constitution,” Barenblatt, 360 U.S. at 111, Congress may
investigate only those topics on which it could legislate, see
Quinn, 349 U.S. at 161 (stating that Congress’s “power to
investigate” does not “extend to an area in which Congress is
forbidden to legislate”). If no constitutional statute may be
                               20
enacted on a subject matter, then that subject is off-limits to
congressional investigators.

     And finally, congressional committees may subpoena only
information “calculated to” “materially aid[]” their
investigations. McGrain, 273 U.S. at 177. Even a valid
legislative purpose cannot justify a subpoena demanding
irrelevant material.

     With these principles in mind, we proceed to the
particulars of this case. The Trump Plaintiffs dispute both the
Committee’s authority from the House to issue the subpoena
and the House’s authority under the Constitution to confer the
same. For reasons that shall become clear later, we address
these questions in reverse order.

                              III.
     At the outset, we emphasize that to resolve this case we
need not decide whether the Constitution permits Congress, in
the conduct of a legislative—that is, non-impeachment—
investigation, to issue subpoenas to a sitting President. That
issue is not presented here because, quite simply, the Oversight
Committee has not subpoenaed President Trump. Rather, the
Committee has issued its subpoena to Mazars, an accounting
firm with whom President Trump has voluntarily shared
records from his time as a private citizen, as a candidate, and
as President. Neither the Trump Plaintiffs nor the Department
of Justice argues that the Constitution denies Congress
authority to subpoena non-governmental custodians of the
President’s financial information. Cf. Oral Arg. Tr. 50 (stating
that assuming a committee has authority from the House to
issue a subpoena, the relevant inquiry is whether “the subpoena
ha[s] a legitimate legislative purpose”); id. at 68 (denying that
the President is “absolutely immune from any oversight
whatsoever”); Department Br. 7–8. Nor do the Trump Plaintiffs
                                 21
assert any property rights in, or executive or other recognized
evidentiary privilege over, the subpoenaed information. See
Complaint (failing to assert any claim of privilege or property
right in the subpoenaed materials); Oral Arg. Tr. 15
(confirming that the President asserts no claim of executive
privilege or immunity); see also Couch v. United States, 409
U.S. 322, 335 (1973) (recognizing that “no confidential
accountant-client privilege exists under federal law, and no
state-created privilege has been recognized in federal cases”);
Peerenboom v. Marvel Entertainment, LLC, 148 A.D.3d 531,
532 (N.Y. App. Div. 1st Dep’t 2017) (holding that “[t]here is
no accountant-client privilege in [New York]”). Instead, the
Trump Plaintiffs ask us to do what courts have done ever since
Kilbourn: to determine “[w]hether the Committee’s subpoena
. . . is ‘related to, and in furtherance of, a legitimate task of the
Congress.’” Appellants’ Br. 5 (quoting Watkins, 354 U.S. at
187); see also Department Br. 10 (quoting same).

     Taking up that question, we consider whether the
Oversight Committee is pursuing a legislative, as opposed to a
law-enforcement, objective; whether the Committee is
investigating a subject on which constitutional legislation
“could be had,” McGrain, 273 U.S. at 177; and whether the
challenged subpoena seeks information sufficiently relevant to
the Committee’s legislative inquiry.

                                 A.
     While “[t]he power of the Congress to conduct
investigations is inherent in the legislative process,” Watkins,
354 U.S. at 187, that authority “must not be confused with any
of the powers of law enforcement,” which “are assigned under
our Constitution to the Executive and the Judiciary,” Quinn,
349 U.S. at 161. The Trump Plaintiffs contend that the
Committee has crossed this constitutional line, veering from
permissible legislative investigation into impermissible law
                                22
enforcement. In assessing whether Congress has strayed
outside its legislative lane, we face two analytical hurdles.

     First, the case law is quite stingy in describing what
impermissible congressional law enforcement might look like
in practice. The Supreme Court has framed its primary
instruction on this point in the negative: the fact that an
investigation might expose criminal conduct does not
transform a legislative inquiry into a law-enforcement
endeavor. As the Court explained in Sinclair, Congress’s
“authority . . . to require pertinent disclosures in aid of its own
constitutional power is not abridged” merely “because the
information sought to be elicited may also be of use” in
criminal prosecutions. 279 U.S. at 295. “Nor [is] it a valid
objection,” said the Court in McGrain, that an investigation
“might possibly disclose crime or wrongdoing.” 273 U.S. at
179–80. Indeed, thanks to the Court’s clarity on this matter, all
parties here agree that “a permissible legislative investigation
does not become impermissible merely because it might expose
law violations.” Appellants’ Br. 33 (internal quotation marks
omitted); see also Appellee’s Br. 44 (“The fact that the . . .
underlying conduct might also be unlawful . . . does not
invalidate the inquiry.”).

     Second, the Supreme Court has made plain that “in
determining the legitimacy of a congressional act,” courts may
“not look to the motives alleged to have prompted it.” Eastland,
421 U.S. at 508; see also Watkins, 354 U.S. at 200 (stating that
“a solution to our problem is not to be found in testing the
motives of committee members for [legislative] purpose”);
Barenblatt, 360 U.S. at 132 (“So long as Congress acts in
pursuance of its constitutional power, the Judiciary lacks
authority to intervene on the basis of the motives which spurred
the exercise of that power.”). This is true both because “it is not
for [the courts] to speculate as to the motivations that may have
                               23
prompted the decision of individual [committee] members,”
Wilkinson v. United States, 365 U.S. 399, 412 (1961), and
because, in any event, those “motives alone would not vitiate
an investigation which had been instituted by a House of
Congress if that assembly’s legislative purpose is being
served,” Watkins, 354 U.S. at 200. On this point, too, the parties
agree. See Appellants’ Reply Br. 11 (“To determine whether a
subpoena is pursuing [the] impermissible goal” of law
enforcement, “courts . . . cannot delve into legislators’ hidden
motives . . . .”); Appellee’s Br. 43 (“[C]ourts cannot examine
Congress’s motives to determine the validity of a subpoena.”).

     Thus stranded between Charybdis and Scylla, we must
determine whether Congress’s “legislative purpose is being
served,” Watkins, 354 U.S. at 200, without taking into account
either whether the investigation will reveal, or whether the
investigators are motivated to reveal, criminal conduct.
According to the Committee, the way out of this dilemma is
simple: just “‘presume Congress is acting in furtherance of its
constitutional responsibility to legislate and . . . defer to
congressional judgments about what Congress needs to carry
out that purpose.’” Appellee’s Br. 46 (quoting Trump, 380 F.
Supp. 3d at 82). In most cases, such a presumption would be
entirely appropriate. As the Court instructed in Tenney v.
Brandhove, “[t]o find that a committee’s investigation has
exceeded the bounds of legislative power it must be obvious
that there was a usurpation of functions exclusively vested in
the Judiciary or the Executive,” 341 U.S. 367, 378 (1951)
(emphasis added); or, as it said in McGrain, even absent an
“express avowal” by Congress that the purpose of an
“investigation was to aid it in legislating,” “the presumption
should be indulged that this was the real object,” 273 U.S. at
178.
                                 24
     The trouble, however, is that this deferential presumption
finds its roots in the principle that “every reasonable
indulgence of legality must be accorded to the actions of a
coordinate branch of our Government,” Watkins, 354 U.S. at
204, and here, we arguably confront not one but two
“coordinate branch[es] of our Government”—Congress and
the President. We say “arguably” because it is far from obvious
that President Trump, proceeding in his individual capacity,
carries the mantle of the Office of the President in this case.
The challenged subpoena seeks financial records totally
unrelated to any of the President’s official actions; indeed, for
six of the eight years covered by the subpoena, President
Trump was merely Mr. Trump or Candidate Trump. Cf.
Clinton v. Jones, 520 U.S. 681, 697 (1997) (“[W]e have never
suggested that the President . . . has an immunity that extends
beyond the scope of any action taken in an official capacity.”).
That said, the fact remains that the constitutional authority
assigned to the Office of the President can be exercised only by
the flesh-and-blood human occupying that office, so as a
practical matter, a restriction on the person might constrain the
branch of government. Cf. In re Lindsey, 158 F.3d 1263, 1286
(D.C. Cir. 1998) (“Because the Presidency is tied so tightly to
the persona of its occupant[,] . . . official matters . . . often have
personal implications for a President” and vice versa.) (Tatel,
J., concurring in part and dissenting in part). In short, although
the challenged subpoena, which seeks financial documents
related to President Trump in his pre-presidential, private
capacities, presents no direct inter-branch dispute, separation-
of-powers concerns still linger in the air. Cf. United States v.
Nixon, 418 U.S. 683, 702 (1974) (explaining that where a
pretrial “subpoena is directed to a President of the United
States, appellate review, in deference to a coordinate branch of
Government, should be particularly meticulous”).
                                25
     Assuming for the moment that we owe Congress no
deference, we must figure out how to assess whether the
subpoena serves “a valid legislative purpose,” Barenblatt, 360
U.S. at 127, without resorting to the “presumption” “that
[legislation] was the real object” of Congress’s investigation,
McGrain, 273 U.S. at 178. The Trump Plaintiffs, arguing that
“‘purpose’ and ‘motive’” are different, suggest that we may
rely upon “available evidence”—that is, “what [the
Committee] is doing and what it has stated publicly”—to
“discern for [ourselves] what the Committee’s actual purpose
is.” Appellants’ Br. 29–30. Following that course, we conclude
that the public record reveals legitimate legislative pursuits, not
an impermissible law-enforcement purpose, behind the
Committee’s subpoena. As a result, we need not decide
precisely what deference we owe Congress, as we would reach
the same conclusion absent any deference at all.

     We start with Chairman Cummings’s April 12
memorandum, in which he laid out the “need for [the]
subpoena” issued to Mazars. Cummings Memo 1. As the
document most closely tied in time and subject matter to the
subpoena, that memorandum offers a natural starting point for
our analysis. Cf. Shelton v. United States, 404 F.2d 1292, 1297
(D.C. Cir. 1968) (identifying “the opening statement of the
Chairman at [committee] hearings” and the “statements of the
members of the committee” as “‘sources [that might] indicate
the existence of a legislative purpose’” (quoting Wilkinson, 365
U.S. at 410)). The Trump Plaintiffs and the Committee appear
to agree, as does the dissent. See Appellee’s Br. 30–31 (relying
on Chairman Cummings’s memorandum to supply a list of the
subjects of the Committee’s investigations); Appellants’ Reply
Br. 20–21 (dismissing as “retroactive rationalizations”
potential legislative purposes that did not “appear[] in the
Chairman’s memorandum” (alterations and internal quotation
                               26
marks omitted)); Dissenting Op. at 2 (tracing the “reasons” for
the subpoena to Chairman Cummings’s Memo).

     Chairman Cummings’s memorandum identifies four
questions that the subpoena will help answer: “whether the
President may have engaged in illegal conduct before and
during his tenure in office,” “whether [the President] has
undisclosed conflicts of interest that may impair his ability to
make impartial policy decisions,” “whether [the President] is
complying with the Emoluments Clauses of the Constitution,”
and “whether [the President] has accurately reported his
finances to the Office of Government Ethics and other federal
entities.” Cummings Memo 4. But even more important than
this list, the Chairman’s very next sentence explains that “[t]he
Committee’s interest in these matters informs [the
Committee’s] review of multiple laws and legislative proposals
under [its] jurisdiction.” Id. Such an “express avowal of the
[Committee’s] object” offers strong evidence of the
Committee’s legislative purpose. McGrain, 273 U.S. at 178.

     The April memorandum does not stand alone. Just two
months earlier, Chairman Cummings articulated the same
remedial legislative objective in his letter to White House
Counsel. In that letter, he explained that obtaining the
requested financial documents would “help the Committee
determine why the President failed to report . . . payments and
whether reforms are necessary to address deficiencies with
current laws, rules, and regulations.” Cummings Feb. 15 Letter
9. “Since the earliest days of our republic,” the Chairman
emphasized, “Congress has investigated how existing laws are
being implemented and whether changes to the laws are
necessary.” Id. And “[f]or decades,” he concluded, “this has
included laws relating to financial disclosures required of the
President.” Id.
                              27
      What’s more, although the House is under no obligation to
enact legislation after every investigation, the fact that the
House has pending several pieces of legislation related to the
Committee’s inquiry offers highly probative evidence of the
Committee’s legislative purpose. See In re Chapman, 166 U.S.
661, 670 (1897) (“[I]t is certainly not necessary” to identify
future legislation “in advance.”); see also Eastland, 421 U.S.
at 509 (“The very nature of the investigative function—like any
research—is that it takes the searchers up some ‘blind alleys’
and into nonproductive enterprises.”). The House has already
passed one such bill, H.R. 1, which requires Presidents to list
on their financial disclosures the liabilities and assets of any
“corporation, company, firm, partnership, or other business
enterprise in which” they or their immediate family have “a
significant financial interest.” H.R. 1, 116th Cong. § 8012
(2019). Another bill currently pending, H.R. 706, would
require both sitting Presidents and presidential candidates to
“submit to the Federal Election Commission a copy of the
individual’s income tax returns” for the preceding nine or ten
years, respectively. H.R. 706, 116th Cong. § 222 (2019). And
still another, H.R. 745, would amend the Ethics in Government
Act to make the Director of the Office of Government Ethics
removable only for cause. See H.R. 745, 116th Cong. § 3
(2019) (making the Director “subject to removal only for
inefficiency, neglect of duty, or malfeasance in office”).

    Despite these indicia of legislative purpose, the Trump
Plaintiffs contend that “[t]he subpoena’s actual purpose is law
enforcement.” Appellants’ Reply Br. 9 (emphasis added). They
make four principal arguments.

    First, the Trump Plaintiffs question whether the
Committee’s avowals of legislative purpose are genuine.
Quoting our court’s opinion in Shelton v. United States, they
argue that “Congress cannot cure [a] constitutional violation
                               28
through ‘the mere assertion of a need to consider remedial
legislation.’” Appellants’ Br. 34 (quoting Shelton, 404 F.2d at
1297). But the Trump Plaintiffs stop at a key conjunction.
“[T]he mere assertion of a need to consider ‘remedial
legislation’ may not alone justify an investigation,” we
explained in Shelton. 404 F.2d at 1297. “[B]ut,” we continued,
“when the purpose asserted is supported by references to
specific problems which in the past have been or which in the
future could be the subjects of appropriate legislation, then we
cannot say that a committee of the Congress exceeds its broad
power.” Id. (emphasis added).

     That is just this case. We do not confront an insubstantial,
makeweight assertion of remedial purpose. To the contrary,
Chairman Cummings’s April 12 memorandum to his
colleagues lists four investigative topics; his March 20 letter to
Mazars details several “specific concerns raised by the [firm’s]
financial statements,” Cummings Mar. 20 Letter 2; and his
February 15 letter to White House Counsel states his intent to
assess whether “changes to the laws . . . relating to financial
disclosures required of the President” “are necessary,”
Cummings Feb. 15 Letter 9. These “references to specific
problems,” Shelton, 404 F.2d at 1297, together with actual
legislation now pending, see supra at 26–27, are more than
sufficient to demonstrate the Committee’s interest in
investigating possible remedial legislation.

     Second, the Trump Plaintiffs contend that, far from
“avow[ing]” a legislative intent, McGrain, 273 U.S. at 178,
Chairman Cummings’s memorandum and statements by other
Representatives have “affirmatively and definitely avowed an
unlawful law-enforcement purpose,” Appellants’ Reply Br. 13
(internal quotation marks omitted); see also Dissenting Op. at
43. In particular, the Trump Plaintiffs take issue with the first
investigative rationale offered in Chairman Cummings’s
                                  29
memorandum: “to investigate whether the President may have
engaged in illegal conduct before and during his tenure in
office.” Cummings Memo 4. But even if such an investigation
would not by itself serve a legitimate legislative purpose, we
can easily reject the suggestion that this rationale spoils the
Committee’s otherwise valid legislative inquiry. Simply put, an
interest in past illegality can be wholly consistent with an intent
to enact remedial legislation.

     Take Hutcheson v. United States, in which the Court
considered the activities of a Senate committee tasked with
“investigat[ing] . . . the extent to which criminal . . . practices
or activities” were occurring “in the field of labor-management
relations” and “determin[ing] whether any changes [were]
required in the laws . . . to protect . . . against . . . such practices
or activities.” 369 U.S. 599, 600–01 (1962) (quoting S. Res. 74,
85th Cong. (1957)). The president of the United Brotherhood
of Carpenters and Joiners of America, called before the
committee to testify regarding whether he had used “union
funds . . . to ‘fix’ a 1957 criminal investigation . . . by a state
grand jury,” id. at 603, refused to answer such questions and
was convicted of criminal contempt, see id. at 605. Even
though “[t]he Committee’s concern . . . was to discover
whether . . . [union] funds . . . had been used . . . to bribe a state
prosecutor,” and even though “[i]f these suspicions were
founded, they might . . . have warranted a separate state
prosecution for obstruction of justice,” the Supreme Court
nonetheless affirmed the contempt conviction. Id. at 617–18.
What mattered to the Court was that the committee’s
investigation into the details of the defendant’s illegal conduct
“would have supported remedial federal legislation for the
future.” Id. at 617. “[S]urely,” the Court concluded, “a
congressional committee . . . engaged in a legitimate legislative
investigation need not grind to a halt whenever . . . crime or
                                30
wrongdoing is disclosed.” Id. at 618 (internal citations
omitted).

     Sinclair teaches a similar lesson. Shortly before the Senate
summoned the oil tycoon Sinclair to testify, it had passed a
joint resolution “recit[ing] that [his company’s] leases . . . were
executed under circumstances indicating fraud and corruption”
and “direct[ing] the President . . . to prosecute such . . .
proceedings, civil and criminal, as were warranted by the
facts.” 279 U.S. at 289. When Sinclair appeared for the hearing,
the Senate committee considered but rejected a motion that
would have prohibited “inquir[ies] . . . relat[ing] to pending
controversies before any of the Federal courts in which Mr.
Sinclair [was] a defendant.” Id. at 290. “If we do not examine
Mr. Sinclair about those matters,” one committee member
lamented, “there is not anything else to examine him about.”
Id. Despite all this, the Court held that “[t]he record [did] not
sustain [Sinclair’s] contention that the investigation was
avowedly not in aid of legislation.” Id. at 295. The failed
motion and the member’s statement were “not enough to show
that the committee intended to depart from the purpose to
ascertain whether additional legislation might be advisable,”
explained the Court, because “[i]t [was] plain that investigation
of the matters involved in” pending or future “suits . . . might
directly aid in respect of legislative action.” Id.

     So too here. Like the committees in Hutcheson and
Sinclair, the Oversight Committee has expressed an interest in
determining whether and how illegal conduct has occurred. But
also like the committees in Hutcheson and Sinclair—indeed,
even more so—the Oversight Committee has repeatedly
professed that it seeks to investigate remedial legislation. In
fact, the House has even put its legislation where its mouth is:
it has passed one bill pertaining to the information sought in
the subpoenas and is considering several others. See supra at
                               31
26–27. The Committee’s interest in alleged misconduct,
therefore, is in direct furtherance of its legislative purpose.

      Third, the Trump Plaintiffs argue that the subpoena’s
“laser-focus[] on the businesses and finances of one person”
evinces “a particularity that is the hallmark of executive and
judicial power.” Appellants’ Br. 35. But again, Supreme Court
precedent forecloses this contention. In McGrain, for example,
the Senate authorized a select committee “to investigate . . . the
alleged failure of Harry M. Daugherty, Attorney General of the
United States, to prosecute properly violators of” anti-trust
laws and “further directed [the committee] to inquire into,
investigate and report . . . the activities of the said Harry M.
Daugherty, Attorney General, and any of his assistants . . .
which would in any manner tend to impair their efficiency or
influence as representatives of the government of the United
States.” 273 U.S. at 151–52 (internal quotation marks omitted).
Untroubled by the resolution’s “direct reference to the then
Attorney General by name,” the Court held that “the resolution
and proceedings” of the investigatory committee “g[a]ve no
warrant for thinking the Senate was attempting or intending to
try the Attorney General . . . before its committee for any crime
or wrongdoing.” Id. at 179.

      The lesson of McGrain is that an investigation may
properly focus on one individual if that individual’s conduct
offers a valid point of departure for remedial legislation. Again,
such is the case here. It is not at all suspicious that the
Committee would focus an investigation into presidential
financial disclosures on the accuracy and sufficiency of the
sitting President’s filings. That the Committee began its inquiry
at a logical starting point betrays no hidden law-enforcement
purpose.

    Finally, the Trump Plaintiffs detect something untoward in
                                 32
the Committee’s interest in the President’s finances. “If this
subpoena is valid,” they argue, “then Congress is free to
investigate every detail of a President’s personal life, with
endless subpoenas to his accountants, bankers, lawyers,
doctors, family, friends, and anyone else with information that
a committee finds interesting.” Appellants’ Reply Br. 24.

     But unlike a subpoena to, say, a doctor or an attorney, the
congressional request at issue in this case implicates no
material subject to a recognized legal privilege or an asserted
property interest. See supra at 20. Moreover, as the Court
explained in Sinclair, although Congress may not make
“unauthorized, arbitrary or unreasonable inquiries” into
individuals’ “personal and private affairs,” Congress most
assuredly does possess authority “to require pertinent
disclosures in aid of its . . . constitutional power” when those
affairs become a “matter of [public] concern” amenable to a
legislative solution. 279 U.S. at 292, 294–95; see also
Barenblatt, 360 U.S. at 127 (explaining that “Congress
may . . . constitutionally require an individual to disclose his
political relationships or other private affairs” if “in relation to”
“a valid legislative purpose”). The same rationale applies here.
Whether current financial disclosure laws are successfully
eliciting the right information from the sitting President,
occupant of the highest elected office in the land, is
undoubtedly “a matter of concern to the United States.”
Sinclair, 279 U.S. at 294; cf. Washington Post Co. v. U.S.
Department of Health & Human Services, 690 F.2d 252, 265
(D.C. Cir. 1982) (“[T]he [Ethics in Government] Act shows
Congress’ general belief that public disclosure of conflicts of
interest is desirable despite its cost in loss of personal
privacy.”).

    In its amicus brief, the Justice Department argues that the
subpoena is invalid for still another reason, namely that the
                                33
House (or at least the Committee) failed to offer a “clear,
specific statement . . . of the legislative purpose that it believes
justifies its subpoena.” Department Br. 12 (emphasis added).
In the Department’s view, general indicia of legislative purpose
are not enough; the House must identify “with sufficient
particularity the subject matter of potential legislation.” Id. at
14. In support, the Department cites Watkins, where, it argues,
“the Supreme Court demanded just such a clear statement of
purpose.” Id. at 13. But the Watkins Court demanded no such
thing. That case concerned not the legitimacy of an
investigative subpoena, but rather an appeal of a criminal
conviction for contempt of Congress under 2 U.S.C. § 192,
which makes it a misdemeanor to refuse to answer any question
posed by a member of Congress “pertinent to the question
under inquiry.” Watkins, 354 U.S. at 207 (quoting 2 U.S.C.
§ 192). Because the committee’s “authorizing resolution, the
remarks of the chairman or members of the committee, [and]
even the nature of the proceedings themselves,” id. at 209,
failed to articulate “the ‘question under inquiry,’” id. at 214,
the Court reversed the conviction, holding that an individual
risking criminal contempt must “have knowledge of the subject
to which the interrogation is deemed pertinent . . . with the same
degree of explicitness and clarity that the Due Process Clause
requires in the expression of any element of a criminal
offense.” Id. at 208–09. The fact that the Watkins Court probed
the committee’s statements in an attempt to remedy “the vice
of vagueness”—present for criminal contempt of Congress, “as
in all other crimes,” id. at 209—provides no support for the
Department’s contention that Congress must identify its
legislative purpose “with sufficient particularity” in order to
justify an investigative subpoena. See Barenblatt, 360 U.S. at
123 (explaining that in Watkins, the Court “rest[ed] [its]
decision on [the] ground” that “a conviction for contempt
under 2 U.S.C. § 192 cannot stand unless the questions asked
are pertinent to the subject matter of the investigation”).
                               34

      Far from finding support in Watkins, the Department’s
argument conflicts with binding Supreme Court precedent.
Over a century ago, the Court made clear in In re Chapman that
it is “certainly not necessary that the resolutions should declare
in advance what the [Congress] meditate[s] doing when the
investigation [i]s concluded.” 166 U.S. at 670. The Court has
twice reiterated this holding, stating in McGrain that “it was
not essential that the Senate declare in advance what it
meditated doing,” 273 U.S. at 172, and then in Eastland—
issued nearly two decades after Watkins—that “to be a valid
legislative inquiry there need be no predictable end result,” 421
U.S. at 509. After all, the purpose of an investigation, as the
Court explained in McGrain, is to gather “information
respecting the conditions which the legislation is intended to
affect or change,” 273 U.S. at 174–75; it is, as the Court added
in Eastland, “research” that informs future Congressional
action, 421 U.S. at 509. Congress’s decision whether, and if so
how, to legislate in a particular area will necessarily depend on
what information it discovers in the course of an investigation,
and its preferred path forward may shift as members educate
themselves on the relevant facts and circumstances. Requiring
Congress to state “with sufficient particularity” the legislation
it is considering before it issues an investigative subpoena
would turn the legislative process on its head.

     Moreover, it is not at all clear what such a statement would
accomplish. The Department suggests that a clear statement
rule is “mandate[d]” by the “particular separation-of-powers
issues that arise when Congress attempts to compel the
President to produce information.” Department Br. 9. Setting
aside the fact that this subpoena, which is addressed to Mazars,
“compel[s] the President to produce” nothing, we still see no
justification in the Department’s brief for why specificity is
required in this scenario as opposed to any other. To be sure,
                               35
“[t]he President occupies a unique position in the constitutional
scheme.” Nixon v. Fitzgerald, 457 U.S. 731, 749 (1982). But
that unique position has little bearing on our ability to
determine whether Congress has strayed from the realm of
legitimate legislation into improper law enforcement—an
inquiry that, as we have just demonstrated, we can
meaningfully conduct without the specific articulation the
Department seeks. Nor does the Department explain how
specificity would meaningfully protect the President beyond
simply burdening Congress’s exercise of its own Article I
power.

      The Department’s argument also ignores how much
Congress has already revealed about its legislative objectives.
In his February 15 letter and April 12 memorandum, Chairman
Cummings explained that the Committee was reviewing
“multiple laws and legislative proposals under [its]
jurisdiction,” Cummings Memo 4, including whether “changes
. . . are necessary” to “laws relating to financial disclosures
required of the President,” Cummings Feb. 15 Letter 9. The
House has already passed H.R. 1, which would require
Presidents to disclose businesses in which they or their
immediate families have significant interests, and is
considering legislation which would require Presidential
candidates and Presidents to submit their income tax returns to
the Federal Election Commission and make the Director of the
Office of Government Ethics removable only for cause. See
supra at 26–27. To be sure, as the Department points out, the
House passed H.R. 1 without the information the subpoena
seeks. But House passage is far from the end of the legislative
process. Information revealed by the subpoena could inform
the Senate as it considers the bill, as well as any subsequent
conference committee or the House itself, should it reconsider
the bill post-conference.
                               36
     Based on all the foregoing, we conclude that in issuing the
challenged subpoena, the Committee was engaged in a
“legitimate legislative investigation,” Hutcheson, 369 U.S. at
618, rather than an impermissible law-enforcement inquiry.
We next assess whether that legislative investigation concerned
a subject “on which legislation could be had.” McGrain, 273
U.S. at 177.

                               B.
     Because “Congress may only investigate into those areas
in which it may potentially legislate or appropriate,”
Barenblatt, 360 U.S. at 111, a congressional committee may
issue only those subpoenas that are “intended to gather
information about a subject on which legislation may be had,”
Eastland, 421 U.S. at 508; see also McGrain, 273 U.S. at 177
(stating that “the subject” of investigation “was one on which
legislation could be had”). The Trump Plaintiffs argue that the
challenged subpoena fails this test because, in their view, “[t]he
subpoena could not result in valid legislation regarding the
President.” Appellants’ Reply Br. 17.

     In addressing this argument, we emphasize that the
relevant inquiry is whether legislation “may be had,” Eastland,
421 U.S. at 508 (emphasis added), not whether constitutional
legislation will be had. Accordingly, we first define the
universe of possible legislation that the subpoena provides
“information about,” id., and then consider whether Congress
could constitutionally enact any of those potential statutes.

    We must, however, tread carefully. As the Committee
points out, our limited judicial role gives us no authority to
reach out and “[s]trik[e] down a statute before it is even
enacted.” Appellee’s Br. 41; see also Nashville, Chattanooga
& St. Louis Railway v. Wallace, 288 U.S. 249, 262 (1933)
(explaining that courts may not make “abstract
                                37
determination[s] . . . of the validity of a statute” or issue
“decision[s] advising what the law would be on an uncertain or
hypothetical state of facts”). That said, as the Trump Plaintiffs
observe, see Appellants’ Br. 21 (“[b]ecause valid legislation
could not ‘be had’ if it would be unconstitutional, the court
ha[s] to decide whether this subpoena is designed to advance
unconstitutional legislation”), the only way to determine
whether the Committee’s investigation informs “a subject on
which legislation may be had” is to ask, abstract as the inquiry
may be, whether “legislation may be had” on that “subject,”
Eastland, 421 U.S. at 508 (emphasis added). Although we must
avoid passing on the constitutionality of hypothetical statutes,
we must also fulfill our responsibility to decide the case in front
of us, even if the road to resolution passes through an issue of
constitutional law. See Cohens v. Virginia, 19 U.S. 264, 404
(1821) (“The judiciary cannot, as the legislature may, avoid a
measure because it approaches the confines of the
[C]onstitution. . . . [W]e must decide [a case] if it be brought
before us.”). Accordingly, in order to resolve this case, we need
to identify a statutory litmus test. The Committee and the
Trump Plaintiffs each offer one, but neither quite fits our needs.

      The Committee urges us to consider whether any law
“concerning government ethics and conflicts of interest
affecting Executive Branch officials” could pass constitutional
muster. Appellee’s Br. 30. But this test is too broad. The
challenged subpoena—or, more specifically, the portion of the
subpoena that seeks a sitting President’s financial
information—would produce no relevant “information about,”
id., laws that apply to ordinary Executive Branch employees.
Because “[t]he President occupies a unique position in the
constitutional scheme,” Fitzgerald, 457 U.S. at 749,
Congress’s constitutional authority to regulate the President’s
conduct is significantly more circumscribed than its power to
regulate that of other federal employees, see supra at 35–36.
                                 38
Just as a congressional committee could not subpoena the
President’s high school transcripts in service of an
investigation into K-12 education, nor subpoena his medical
records as part of an investigation into public health, it may not
subpoena his financial information except to facilitate an
investigation into presidential finances. Thus, to determine
whether the records of pre-Candidate, Candidate, and President
Trump provide “information about a subject on which
legislation may be had,” Eastland, 421 U.S. at 508, we must
train our attention on laws that apply to Presidents (and
presidential hopefuls).

     In that vein, the Trump Plaintiffs urge us to focus on the
constitutionality of laws that “impose conflict-of-interest
restrictions on the President.” Appellants’ Br. 37. As the Trump
Plaintiffs point out, such restrictions raise difficult
constitutional questions. Statutes mandating divestment from
financial interests or recusal from conflicted matters might
impermissibly “disempower [Presidents] from performing
some of the functions prescribed [by] the Constitution or . . .
establish a qualification for . . . serving as President . . . beyond
those contained in the Constitution.” Memorandum from
Laurence H. Silberman, Deputy Attorney General, to Richard
T. Burress, Office of the President, Re: Conflict of Interest
Problems Arising out of the President’s Nomination of Nelson
A. Rockefeller to be Vice President Under the Twenty-Fifth
Amendment to the Constitution 5 (Aug. 28, 1974) (“Silberman
Memo”). But we need not grapple with those constitutional
issues because the Mazars subpoena seeks information related
to a class of statutes that impose far fewer burdens than laws
requiring Presidents to change their behavior based on their
financial holdings. This less burdensome species of law would
require the President to do nothing more than disclose financial
information. Such statutes might amend the Ethics in
Government Act, for example, to require Presidents and
                               39
presidential candidates to file reports more frequently, to
include information covering a longer period of time, or to
provide new kinds of information such as past financial
dealings with foreign businesses or current liabilities of closely
held companies. We take this category of statutes as the
appropriate object of our litmus test in this case.

     The Trump Plaintiffs argue that the Constitution prohibits
even these. Relying on Chief Justice Burger’s concurrence in
Nixon v. Fitzgerald, they contend that financial disclosure laws
unconstitutionally “‘impinge[] on and hence interfere[] with
the independence that is imperative to the functioning of the
office of a President.’” Appellants’ Br. 44 (quoting Fitzgerald,
457 U.S. at 761 (Burger, C.J., concurring)).

      But that is not the rule—at least not quite. As the Court
explained in Nixon v. Administrator of General Services (Nixon
II), the mere act of “regulat[ing] . . . Presidential materials,”
“without more,” does not “constitute[] . . . a violation of the
principle of separation of powers.” 433 U.S. 425, 441 (1977).
Instead, rejecting “the argument that the Constitution
contemplates a complete division of authority between the
three branches,” the Court reaffirmed its reliance on “the more
pragmatic, flexible approach of Madison in the Federalist[]
Papers.” Id. at 442–43. “In . . . dividing and allocating the
sovereign power among three coequal branches,” the Court
explained, “the Framers of the Constitution” did not intend “the
separate powers . . . to operate with absolute independence.”
Id. at 443 (internal quotation marks and emphasis omitted). The
Court therefore announced the following test: “in determining
whether [a statute] disrupts the proper balance between the
coordinate branches, the proper inquiry focuses on the extent
to which it prevents the Executive Branch from accomplishing
its constitutionally assigned functions.” Id. Applying this rule,
we have no basis for concluding that complying with financial
                                 40
disclosure laws would in any way “prevent[] the [President]
from accomplishing [his] constitutionally assigned functions.”
Id.

      The most persuasive evidence on this score comes from
the Constitution itself. The very same document that “vest[s]”
“[t]he executive Power . . . in [the] President,” U.S. Const.
art. II, § 1, cl. 1, and directs him to “take Care that the Laws be
faithfully executed,” id. art. II, § 3, also imposes two separate
requirements pertaining to the President’s private finances. The
first, the so-called Domestic Emoluments Clause, prohibits the
President from receiving “any . . . Emolument” from the
federal or state governments other than a fixed
“Compensation” “for his Services.” Id. art. II, § 1, cl. 7. And
the second, the so-called Foreign Emoluments Clause,
prohibits any federal official “holding any Office of Profit or
Trust”—the President included—from “accept[ing] . . . any
present, Emolument, Office, or Title, of any kind whatever,
from any King, Prince, or foreign State” without “the Consent
of the Congress.” U.S. Const. art. I, § 9, cl. 8; see also
Applicability of the Emoluments Clause & the Foreign Gifts &
Decorations Act to the President’s Receipt of the Nobel Peace
Prize, O.L.C. slip op. at 4, 2009 WL 6365082, at *4 (Dec. 7,
2009) (“The President surely ‘hold[s] an[] Office of Profit or
Trust’ . . . .” (alterations in original) (quoting U.S. Const. art. I,
§ 9, cl. 8)). If the President may accept no domestic
emoluments and must seek Congress’s permission before
accepting any foreign emoluments, then surely a statute
facilitating the disclosure of such payments lies within
constitutional limits.

     The United States Code, too, provides ample precedent for
laws that regulate Presidents’ finances and records. Cf. Nixon
II, 433 U.S. at 445 (noting the “abundant statutory precedent
for the regulation and mandatory disclosure of documents in
                               41
the possession of the Executive Branch”). The Foreign Gifts
and Decorations Act requires all federal employees, including
the President, to “file a statement” regarding any gift they
receive “of more than minimal value.” 5 U.S.C. § 7342(c). The
STOCK Act prohibits all “executive branch employees,”
including the President, from “us[ing] nonpublic information
derived from such person’s position . . . as a means for making
a private profit.” Pub. L. No. 112-105, §§ 2, 9, 126 Stat. 291,
291, 297. And the Presidential Records Act—whose
constitutionality the Trump Plaintiffs readily concede—
establishes a whole statutory scheme for “categoriz[ing],”
“fil[ing],” “dispos[ing]” of, and “manag[ing]” “Presidential
records.” 44 U.S.C. § 2203; see Appellants’ Br. 40 (“The
Presidential Records Act . . . did not cause a disruption of
executive functions significant enough to trigger separation of
powers analysis” (internal quotation marks omitted)). History
discloses no evidence that these statutes have disrupted
presidential functions.

     The history of past Presidents’ financial disclosures offers
a particularly useful guide. As explained above, see supra at 3–
4, the Ethics in Government Act requires Presidents to file
periodic reports detailing, among other things, “[t]he source,
type, and [approximate] amount or value of income . . . from
any [non-federal] source,” “[t]he identity and [approximate]
value of . . . total liabilities owed,” and “the date . . . and
[approximate] value of any purchase, sale or exchange [of real
property and securities] during the preceding calendar year.”
5 U.S.C. app. 4 § 102(a). Every President to have served since
the Ethics in Government Act became law in 1978—Presidents
Carter, Reagan, H.W. Bush, Clinton, W. Bush, Obama, and
now Trump—has complied with these disclosure requirements.
See, e.g., Philip Taubman, Carter Drops ‘Blind Trust’ Secrecy
and Divulges Finances for 1978-9, N.Y. Times, May 31, 1979,
at A1; Edward T. Pound, Reagan’s Worth Put at $4 Million,
                               42
N.Y. Times, Feb. 23, 1981, at A1; Associated Press,
President’s Trust Grows in Value, N.Y. Times, May 15, 1992,
at A17; Stephen Labaton, Most of Clintons’ Wealth Held by
Mrs. Clinton, Disclosure Form Shows, N.Y. Times, May 18,
1994, at A20; Richard W. Stevenson, Bushes’ Assets Put at
$8.8 Million in Filing, N.Y. Times, May 16, 2003, at A22; U.S.
Office of Government Ethics, Presidential and Vice
Presidential        Financial        Disclosure          Reports,
https://extapps2.oge.gov/201/Presiden.nsf/President%20and%
20Vice%20President%20Index (financial disclosure reports of
Presidents Obama and Trump); see also Appellants’ Br. 44
(acknowledging that “President [Trump] has voluntarily
complied with those statutory requirements”). In fact,
Presidents Carter, Reagan, H.W. Bush, Clinton, W. Bush, and
Obama exceeded statutory disclosure requirements by
releasing their personal federal income tax returns to the public.
See       Presidential       Tax      Returns,         TaxNotes,
taxnotes.com/presidential-tax-returns (collecting presidential
tax records).

     Of course, as the Trump Plaintiffs point out, “compliance
is not the measure of constitutionality.” Appellants’ Br. 44. But
when asked to decide whether an act of Congress “disrupts the
proper balance between the coordinate branches,” Nixon II, 433
U.S. at 443, a court would be foolish to ignore those branches’
prior pattern of conflict—or, as here, cooperation. See id. at 441
(finding it significant that “[n]either President Ford nor
President Carter support[ed] [former-President Nixon’s]
claim” that the challenged statute’s “regulation of the
disposition of Presidential materials . . . constitutes, without
more, a violation of the principle of separation of powers”); cf.
Zivotofsky v. Kerry, 135 S. Ct. 2076, 2091 (2015) (“In
separation-of-powers cases this Court has often ‘put significant
weight upon historical practice.’” (quoting NLRB v. Noel
Canning, 573 U.S. 513, 524 (2014))). Though not dispositive,
                                43
the fact that every President during the last four decades has
filed financial disclosures offers persuasive evidence that such
disclosures neither “prevent[]” nor “disrupt[],” Nixon II, 433
U.S. at 443, the President’s efforts to “take Care that the Laws
be faithfully executed,” U.S. Const. art. II, § 3.

     To be sure, it is possible that some hypothetical statute
could go too far. One could certainly imagine disclosure
mandates so onerous that they begin to “prevent[] the
Executive Branch from accomplishing its constitutionally
assigned functions.” Nixon II, 433 U.S. at 443; see, e.g., Oral
Arg. Tr. 17 (positing “a statute [requiring] the President . . . to
submit 100,000 pages of financial disclosures and [to] meet
with Congress once a month to discuss them”). But to accept
the Trump Plaintiffs’ suggestion that Congress may impose no
disclosure requirements whatsoever on the President, see Oral
Arg. Tr. 51–52 (stating it is “very difficult to think of” a
constitutional law Congress “could pass” with respect to the
President)—or, put another way, that the challenged subpoena
could result in no valid legislation—would be to return to an
“archaic view of the separation of powers” that “requir[es]
three airtight departments of government,” Nixon II, 433 U.S.
at 443 (internal quotation marks omitted). That is not the law.

     Instead, “our constitutional system imposes upon the
Branches a degree of overlapping responsibility, a duty of
interdependence as well as independence[,] the absence of
which ‘would preclude the establishment of a Nation capable
of governing itself effectively.’” Mistretta v. United States, 488
U.S. 361, 381 (1989) (quoting Buckley v. Valeo, 424 U.S. 1,
121 (1976)). As the Supreme Court has observed, “separation
of powers does not mean that the branches ‘ought to have no
partial agency in, or no controul over, the acts of each other.’”
Clinton, 520 U.S. at 702–03 (quoting The Federalist No. 47, at
325–326 (J. Cooke ed.1961) (emphasis in original)); see also
                              44
Nixon II, 433 U.S. at 442-43 & n.5 (affirming “the more
pragmatic, flexible approach of Madison in the Federalist
Papers and later of Mr. Justice Story” to the separation of
powers); Nixon, 418 U.S. at 703 (“In designing the structure of
our Government and dividing and allocating the sovereign
power among three coequal branches, the Framers of the
Constitution sought to provide a comprehensive system, but the
separate powers were not intended to operate with absolute
independence.”). As the Nixon cases teach, the “proper inquiry
focuses on the extent to which [another branch’s actions]
prevent[] the Executive branch from accomplishing its
constitutionally assigned functions.” Nixon II, 433 U.S. at 443
(citing Nixon, 418 U.S. at 711-712). Congress can require the
President to make reasonable financial disclosures without
upsetting this balance.

     The Trump Plaintiffs challenge the constitutionality of
legislation that “may be had” on another basis. Eastland, 421
U.S. at 508. Drawing on the principle announced in Powell v.
McCormack, 395 U.S. 486 (1969), and U.S. Term Limits,
Inc. v. Thornton, 514 U.S. 779 (1995), that “[n]either Congress
nor the states can add to the constitutional qualifications for
holding federal elective office,” Walker v. United States, 800
F.3d 720, 723–24 (6th Cir. 2015), they argue that imposing
conflict-of-interest laws on the President would impermissibly
“change or expand the qualifications for serving as President,”
Appellants’ Br. 38 (citing Powell and Thornton). But once
again, we need not reach this issue. Regardless of whether
Congress may require Presidents to “eliminat[e] [their]
financial conflicts” through divestment or recusal, the Trump
Plaintiffs offer no reason to suspect that a statute requiring
nothing more than disclosure of such conflicts might also
“‘establish a qualification for . . . serving as President.’”
Appellants’ Br. 38 (quoting Silberman Memo 5). Financial
disclosure laws would not, as in Powell, prevent a “duly
                                45
elected” official from assuming office, 395 U.S. at 550, nor, as
in U.S. Term Limits, add a term limit to “the exclusive
qualifications set forth in the text of the Constitution,” 514 U.S.
at 827; cf. Appellants’ Br. 39 (conceding that “[t]he
Presidential Records Act does not add or alter the qualifications
for office”). In the end, laws requiring disclosure exclude
precisely zero individuals from running for or serving as
President; regardless of their financial holdings, all
constitutionally eligible candidates may apply.

     In sum, we detect no inherent constitutional flaw in laws
requiring Presidents to publicly disclose certain financial
information. And that is enough. Without treading onto any
other potentially fertile grounds from which constitutional
legislation could flower, we conclude that given the
constitutionally permissible options open to Congress in the
field of financial disclosure, the challenged subpoena seeks
“information about a subject on which legislation may be had.”
Eastland, 421 U.S. at 508.

     To the dissent, however, this makes no difference.
Although acknowledging that the Committee is pursuing a
“valid legislative inquiry,” the dissent insists that the Mazars
subpoena is nonetheless invalid because it “seeks to investigate
individual suspicions of criminality against the President,” an
inquiry that “may be pursued only through impeachment.”
Dissenting Op. at 44. In support, the dissent claims to rely on
the “text and structure of the Constitution, its original meaning
and longstanding practice.” Id. at 3.

    Of course, the Constitution always serves as our starting
point, and particularly in separation-of-powers disputes, we
“put significant weight upon historical practice.” Zivotofsky,
135 S. Ct. at 2091 (internal quotations omitted). Indeed, this is
a path the Supreme Court and this court have already
                                46
trod. Nearly a century of precedent has laid out an established
test that resolves this inter-branch dispute in a way that, unlike
the dissent, respects the co-equal status and roles of both the
legislative and executive branches. Settled Supreme Court
precedent teaches that—at least where, as here, no party argues
that compliance with the subpoena would impair the
President’s execution of the Article II power—the Constitution
protects both branches’ prerogatives by determining whether
the subpoena serves “a valid legislative purpose.” Barenblatt,
360 U.S. at 127. Both the Trump Plaintiffs and the Department
of Justice agree that this is the relevant inquiry. See Appellants’
Br. 16 (“When Congress issues subpoenas in aid of valid
legislation, it needs a legitimate legislative purpose”);
Department Br. 10. (“The court must first determine whether
the subpoena serves a ‘valid legislative purpose.’”).

     To be sure, a Congress pursuing a legitimate legislative
objective may, as the many examples recounted in the dissent
demonstrate, choose to move from legislative investigation to
impeachment. But the dissent cites nothing in the Constitution
or case law—and there is nothing—that compels Congress to
abandon its legislative role at the first scent of potential
illegality and confine itself exclusively to the impeachment
process. Nor does anything in the dissent’s lengthy recitation
of historical examples dictate that result. All involved
investigations targeted at individual conduct; none involved a
Congressional effort to investigate the need to amend existing
laws or enact remedial legislation. Instead, those examples
merely demonstrate that Congress has, at various points
throughout our history, debated and decided when it wishes to
shift from legislating to impeaching. Where legislation may be
had—and especially here, where bills are pending and no
intrusion on the President’s execution of his official duties is
alleged—the Constitution assigns that decision to Congress.
                               47
     Unable to prevail under the test the Supreme Court has
enforced for more than a century, the dissent moves the
goalposts. The dissent proposes a brand-new test for the
President (and other “impeachable officials,” Dissenting Op. at
44) that would enfeeble the legislative branch. According to the
dissent, once some Members—or perhaps just one Member—
raise “suspicions of criminality” by an impeachable official,
Congress must “end[]” all legislative investigation and either
do nothing at all or “move[] that part of the investigation into
impeachment.” Dissenting Op. at 19.

     In other words, Congress must either initiate the grave and
weighty process of impeachment or forgo any investigation in
support of potential legislation. Under the dissent’s novel test,
“even a valid legislative purpose” cannot “justify” the
investigation. Id. at 19. The dissent identifies nothing in the
text, structure, or original meaning of Article I or Article II of
the Constitution to support such a sweeping rule of legislative
paralysis. As the Trump Plaintiffs and the Department of
Justice agree, the Supreme Court has said just the opposite: “a
congressional committee which is engaged in a legitimate
legislative investigation need not grind to a halt whenever . . .
crime or wrongdoing is disclosed.” Hutcheson, 369 U.S. at 618.

      The dissent tries to house its theory in the Supreme Court’s
decision in McGrain. Quoting the Court’s observation that an
investigation would be invalid “if the Senate was ‘attempting
or intending to try the Attorney General at its bar or before its
committee for crime or wrongdoing,’” the dissent insists that
“[i]t was essential to the Court’s decision that the investigation
did not target the unlawful behavior of the Attorney General,”
Dissenting Op. at 49 (quoting McGrain, 273 U.S. at 179–80)
(emphasis added). But as the sentence quoted by the dissent
reveals, the Court said nothing about “targeting” specific
conduct. Instead, the Court made clear that the investigation
                               48
was not invalid because the authorizing “resolution, like the
charges which prompted its adoption . . . [made] reference to
[the Attorney General] by name,” nor was it “a valid objection
to the investigation that it might possibly disclose crime or
wrongdoing on his part.” McGrain, 273 U.S. at 179–80.
Indeed, the district court in McGrain had adopted the dissent’s
view, invalidating the subpoena because the authorizing
resolution alleged “specific instances of . . . neglect” and the
Senate was “proposing . . . to determine the guilt of the
Attorney General of the shortcomings and wrongdoings set
forth in th[ose] resolutions.” Id. at 177. The Senate was, as the
district court saw it, “exercising the judicial function,” a power
“impliedly negatived by th[e] Constitution, in its provision
conferring the sole power of impeachment on the House of
Representatives.” Ex parte Daugherty, 299 F. 620, 639 (S.D.
Ohio 1924). The Supreme Court labeled this reasoning
“wrong,” explaining “that the object of the investigation . . .
was to obtain information for legislative purposes.” McGrain,
273 U.S. at 177.

     The dissent points to McGrain’s language that “[i]t [wa]s
not as if an inadmissible or unlawful object were affirmatively
and definitely avowed,” arguing that, here, the subpoena is
invalid because “[t]he Committee has ‘affirmatively and
definitely avowed’ its suspicions of criminality against the
President.’” Dissenting Op. at 50–51 (quoting McGrain, 273
U.S. at 180). The dissent misreads that sentence. According to
the Court, the Senate resolution in McGrain sought
“information necessary as a basis for such legislative and other
action as the Senate may deem necessary and proper.” 273
U.S. at 179 (emphasis added). But there was “no other action,”
the Court explained, “which would be within the power of the
Senate.” Id. It was the Senate’s “indefinite and untenable
suggestion” of non-legislative action—not an avowal of
suspicions of individual wrongdoing—that the Court held did
                               49
not “invalidate[] the entire proceeding.” Id. McGrain thus
squarely forecloses the dissent’s theory.

     It is unsurprising that no case law supports the
dissent. Under its view, Congress’s power to investigate, when
it comes to the President and all other impeachable officials,
would no longer be “co-extensive with [its] power to legislate.”
Quinn, 349 U.S. at 160. The dissent would reorder the very
structure of the Constitution. Throughout history, the
Constitution has left to Congress the judgment whether to
commence the impeachment process. But the dissent’s
approach would not even allow Congress to make the
quintessentially legislative judgment that some concerns about
potential misconduct or illegality are better addressed through
oversight and legislation than impeachment. Worse still, the
dissent’s novel approach would now impose upon the courts
the job of ordering the cessation of the legislative function and
putting Congress to the Hobson’s Choice of impeachment or
nothing.

     To be sure, the dissent would still allow Congress to “enact
legislation.” Dissenting Op. at 64. But it would have to do so
uninformed and with its oversight function informationally
crippled. This would mean that, at times when oversight and
legislation are most urgent, such as to prevent executive branch
overreach or to keep officials’ behavior within ethical
boundaries going forward, Congress would be legislatively
hamstrung unless it were to pull the impeachment trigger. And
if Congress chooses not to pursue impeachment, or if
impeachment is unavailable because Congress believes the
alleged misconduct falls short of a high crime or misdemeanor,
then there can be no investigation of—and thus no viable
legislative check on—the President at all. A proposition that so
strips Congress of its power to legislate would enforce only the
Executive’s arrogation of power, not the separation of powers.
                               50
     At bottom, this subpoena is a valid exercise of the
legislative oversight authority because it seeks information
important to determining the fitness of legislation to address
potential problems within the Executive Branch and the
electoral system; it does not seek to determine the President’s
fitness for office.

                               C.
     Thus far we have concluded that the Committee is
pursuing a legislative, non-law-enforcement purpose and that
at least one kind of constitutional legislation may be had on the
subject matter of the Committee’s investigation. What is left to
decide is whether the documents requested in this subpoena are
relevant to that investigation. The Trump Plaintiffs insist that
at least some are not.

    As the Watkins Court described it, the requirement that a
subpoena request only those documents that are relevant to a
committee’s legitimate investigation “is a jurisdictional
concept of pertinency drawn from the nature of a congressional
committee’s source of authority.” 354 U.S. at 206. Though
complex sounding, the relevancy requirement functions merely
as a corollary to the other restraints on congressional
committees’ investigative powers: if a committee could
subpoena information irrelevant to its legislative purpose, then
the Constitution would in practice impose no real limit on
congressional investigations.

     The Supreme Court has used various formulations to
describe the relevancy standard that applies to congressional
subpoenas. In McGrain, the Court held that Congress could
subpoena any information that would “materially aid[]” a
legitimate investigation. 273 U.S. at 177. In Watkins, it
explained that committees may subpoena information “to be
used . . . in coping with a problem that falls within [their]
                               51
legislative sphere.” 354 U.S. at 206. And in McPhaul v. United
States, the Court offered not one but two explanations,
validating a subpoena because, in the Court’s words, the
subcommittee had requested records that “were not plainly
incompetent or irrelevant to any lawful purpose . . . , but, on
the contrary, were reasonably relevant to the inquiry.” 364 U.S.
372, 381–82 (1960) (alterations, citations, and internal
quotation marks omitted). We read all these statements, varied
as they are, as conveying essentially the same straightforward
proposition: Congress may subpoena only that information
which is “reasonably relevant” to its legitimate investigation.
Id.; accord Appellants’ Br. 19 (“If the congressional subpoena
is not ‘reasonably relevant to the inquiry,’ then it lacks a
legitimate purpose.” (quoting McPhaul, 364 U.S. at 381–82)).

    With this standard in mind, we turn to the challenged
subpoena. Recall that it seeks four categories of documents: for
“calendar years 2011 through 2018,” (1) “statements of
financial condition, annual statements, periodic financial
reports, and independent auditors’ reports,” (2) “underlying,
supporting, or source documents and records,” and (3) related
“memoranda, notes, and communications;” and, (4) “[w]ithout
regard to time,” all related “engagement agreements or
contracts.” Subpoena. For clarity, we label these four
categories Accounting Records, Source Documents, Related
Communications, and Engagement Agreements, respectively.
In our view, all are reasonably relevant to remedial legislation
addressing at least two of the topics listed in Chairman
Cummings’s Memo: the President’s potential “undisclosed
conflicts of interest” and the President’s “report[s] . . . to the
Office of Government Ethics and other federal entities.”
Cummings Memo 4.

   We begin with Accounting Records and Source
Documents for calendar years 2014 through 2018. Because
                                52
then-Candidate and now-President Trump filed financial
disclosure reports covering these years, financial records from
this period are highly relevant to the Committee’s inquiry into
whether Candidate and President Trump “accurately reported
his finances to . . . federal entities,” id., and, by extension,
“whether reforms are necessary to address deficiencies with
current laws, rules, and regulations,” Cummings Feb. 15 Letter
9. A clear line connects the Office of Government Ethics’s May
2018 determination that President Trump’s financial disclosure
form failed to list “a reportable liability” to Michael Cohen,
Apol Letter 1; to Chairman Cummings’s January 2019 requests
to the White House and the Office of Government Ethics for
further information on President Trump’s payments to Cohen;
to Cohen’s February 2019 production of Mazars accounting
documents revealing financial information different from and
additional to Candidate and President Trump’s financial
disclosures; and finally to the Committee’s March 2019 request
and April 2019 subpoena to Mazars. From this logical
progression we discern “no indication” that the subpoena
“follow[ed] from indiscriminate dragnet procedures, lacking in
probable cause for belief that” Mazars “possesse[s]
information which might be helpful to the” Committee.
Barenblatt, 360 U.S. at 134. Tellingly, the Trump Plaintiffs
raise no relevance objection to this subset of subpoenaed
documents.

    We next consider the same two categories of records—
Accounting Records and Source Documents—for years 2011
through 2013. According to the Trump Plaintiffs, these
documents are irrelevant to the Committee’s investigation
because they “reach[] back many years before the President
was even a candidate for public office.” Appellants’ Reply Br.
16–17. This is true, but beside the point. The fact that the Ethics
in Government Act currently requires candidates and
Presidents to disclose information for “the preceding calendar
                               53
year,” e.g., 5 U.S.C. app. 4 § 102(b)(1)(A), hardly forecloses
Congress from amending the Act to require filers to go back a
reasonable amount of additional time to provide a more
accurate financial picture. That is especially true here because
the sitting President possesses financial holdings that are
arguably more complex than past Presidents held, has elected
while in office to handle his finances differently than past
Presidents did, and has declined to voluntarily release the sorts
of tax-return information that past Presidents disclosed. See,
e.g., H.R. 1: Strengthening Ethics: Hearing Before the House
Committee on Oversight and Reform, 116th Cong. 125 (Feb. 6,
2019) (statement of Walter M. Shaub, Jr.) (describing the
President’s decision not “to divest his conflicting financial
interests” as a “radical departure” from previous Presidents).

     Congress might therefore reasonably wonder whether the
Ethics in Government Act needs an update, and even pre-
candidacy documents from the President would shed light on
that inquiry. Requiring presidential candidates and Presidents
to disclose earlier years’ information might, for example,
reveal forgiven debts, financial partnerships, or favorable deals
that Congress determines should be disclosed to the public—
that is, “undisclosed conflicts of interest.” Cummings Memo 4.
In fact, at least one bill now pending before the House would
require presidential candidates to “submit to the Federal
Election Commission a copy of [their] income tax returns for
the 10 most recent taxable years.” H.R. 706, 116th Cong.
§ 222(b)(1)(A) (2019).

     Of course, the Committee may discover nothing notable in
Mazars’s 2011 through 2013 records. But that is not the test for
relevancy. As the Supreme Court has explained, “[t]he very
nature of the investigative function—like any research—is that
it takes the searchers up some ‘blind alleys’ and into
nonproductive enterprises.” Eastland, 421 U.S. at 509; see also
                              54
Appellants’ Br. 32 (conceding that “Congress cannot be
penalized if an otherwise valid investigation turns out to be a
dead end”). To be sure, information from the past may at some
point become so stale as to be irrelevant to present inquiries,
but the eight-year mark falls comfortably on the relevant side
of the line.

     We last turn to the Committee’s request for Related
Communications and Engagement Agreements. According to
the Trump Plaintiffs, these documents “have nothing to do with
the financial statements the Committee says it needs.”
Appellants’ Reply Br. 17. But again, we think the records’
relevancy is quite clear. As the Committee explains, the import
of the Mazars accounting documents hinges on the conditions
under which they were prepared—for example, whether
Mazars accepted documents “as a given,” whether Mazars
prepared its reports intending third parties to rely upon them,
and whether Mazars had the “power[] or responsibilit[y]” to
conduct independent audits. Oral Arg. Tr. 108. Obviously not
every “agreement[]” or “note[]” will provide this information.
Subpoena. But absent foreknowledge of the documents’
contents, congressional investigators have no way to reliably
determine before issuing a subpoena which specific
communications might reveal relevant information. It is
enough that the categories of information sought are
“reasonably relevant” to the Committee’s legitimate legislative
inquiry.

                             IV.
     Having found no constitutional defect in the Committee’s
subpoena to Mazars, we at last arrive at the question of
authority: “whether the committee [is] authorized” by the full
House “to exact the information” it seeks. Rumely, 345 U.S. at
42–43; see also Exxon Corp. v. FTC, 589 F.2d 582, 592 (D.C.
Cir. 1978) (“To issue a valid subpoena, . . . a committee or
                                55
subcommittee must conform strictly to the resolution
establishing its investigatory powers.”). The Trump Plaintiffs
urge us to interpret the House Rules narrowly to deny the
Committee the authority it claims. But we have no need—and
most important, no authority—to do so.

                                A.
    We start with the proposition, undisputed by the Trump
Plaintiffs, that under the most natural reading of the House
Rules, the full chamber has authorized the Committee to issue
the challenged subpoena. See Oral Arg. Tr. 38–39 (Trump
Plaintiffs conceding that the Rules, under a “normal reading,”
authorize the subpoena). A brief tour through the Rules
confirms as much.

     To begin with, the Rules vest the Oversight Committee
with standing authority to institute investigations and issue
subpoenas without first “obtain[ing] such authority . . . by a
separate resolution.” House Rules and Manual, 115th Cong.,
§ 788 note (2017); see also Morton Rosenberg, When Congress
Comes Calling: A Study on the Principles, Practices, and
Pragmatics of Legislative Inquiry 33–34 & 34 n.5 (2017)
(explaining that although “[t]he required authorization from the
full House . . . may take the form of a statute, a resolution, or a
standing rule of the House,” “[t]his [last] mode is the most
common today” (footnotes omitted)). Clause 1(b)(1) of House
Rule XI permits “[e]ach committee [to] conduct at any time
such investigations and studies as it considers necessary.” And
Clause 2(m) of the same Rule authorizes committees—or,
when the committees so choose, their chairs—“to require, by
subpoena or otherwise, . . . the production of such books,
records, correspondence, memoranda, papers, and documents
as [they] consider[] necessary” “[f]or the purpose of carrying
out any of [their] functions and duties under . . . rule X.” House
Rule XI, cl. 2(m)(1); see also id. cl. 2(m)(3)(A)(i) (permitting
                               56
committees to “delegate[] to the[ir] chair” “[t]he power to
authorize and issue subpoenas”); Rules of the House
Committee on Oversight and Reform, 116th Cong., Rule 12(g)
(2019) (authorizing the Oversight Committee Chair to “issue
subpoenas as provided in House Rule XI, clause 2(m), in the
conduct of any investigation or activity or series of
investigations or activities within the jurisdiction of the
Committee”).

     Rule X, in turn, establishes the Oversight Committee’s
jurisdiction, which unquestionably includes financial-
disclosure and other ethics-in-government laws. Rule X, clause
1(n) assigns the Committee jurisdiction over the “[f]ederal civil
service . . . and the status of officers and employees of the
United States,” “[g]overnment management and accounting
measures generally,” and “[p]ublic information and records.”
Pursuant to this clause, the Oversight Committee has for
decades exercised jurisdiction over the Ethics in Government
Act and served as the authorizing committee for the Office of
Government Ethics. See, e.g., 165 Cong. Rec. H1209 (daily ed.
Jan. 24, 2019) (referring H.R. 745, a “bill to amend the Ethics
in Government Act of 1978 to provide for reform in the
operations of the Office of Government Ethics, . . . to the
Committee on Oversight and Reform”); Letter from Jason
Chaffetz, Chairman, House Committee on Oversight and
Government Reform, to Walter M. Shaub, Jr., Director, Office
of Government Ethics 2 (Jan. 12, 2017) (stating that the
Oversight Committee “has jurisdiction in the House of
Representatives for reauthorizing the [O]ffice” of Government
Ethics); see also H.R. Rep. No. 95-642, pt. 1 (1977) (report of
the Committee on Post Office and Civil Service, predecessor
to the Oversight Committee, on H.R. 6954, predecessor to the
Ethics in Government Act of 1978). Furthermore, Rule X,
clause 3(i) directs the Oversight Committee to “review and
study on a continuing basis the operation of Government
                                57
activities at all levels, including the Executive Office of the
President.” And lest any confusion remain regarding the
Oversight Committee’s authority to oversee, Rule X,
clause 4(c)(2) states that the Committee “may at any time
conduct investigations of any matter without regard to [any
other] clause conferring jurisdiction over the matter to another
standing committee.”

     Having placed “any matter” within the Oversight
Committee’s wide purview, the Rules nowhere disclose an
intent to carve out the President. It would be quite strange for
the Rules to permit the Oversight Committee to “review and
study,” House Rule X, cl. 3(i), financial disclosure laws in all
their applications save for one—their application to the
President. See 5 U.S.C. app. 4 §§ 101(a), (f)(1), 102 (requiring
the President to file financial reports). So, too, would it be
strange to direct the Committee to oversee “the operation of
Government activities at all levels,” House Rule X, cl. 3(i), if
the Rules really meant “at all levels except the President.” And
although we do not read the second half of clause 3(i), which
specifies that “Government . . . at all levels . . . includ[es] the
Executive Office of the President,” to refer to the President
himself, cf. Kissinger v. Reporters Committee for Freedom of
the Press, 445 U.S. 136, 156 (1980) (holding that in the
Freedom of Information Act, the term “‘Executive Office’ does
not include the Office of the President”), neither do we take the
“including” phrase to imply that “Government activities at all
levels” means something less than “all,” see Federal Land
Bank of St. Paul v. Bismarck Lumber Co., 314 U.S. 95, 100
(1941) (“[T]he term ‘including’ is not one of all-embracing
definition, but connotes simply an illustrative application of the
general principle.”). Indeed, the Trump Plaintiffs urge us to
draw no such negative inference. See Appellants’ Reply Br. 6
(“Plaintiffs do not claim that [adding the] new language
                               58
[‘Executive Office of the           President’]   narrowed    the
Committee’s authority.”).

                               B.
     Acknowledging that literally read, the Rules permit the
Committee to issue the challenged subpoena, see supra at 49,
the Trump Plaintiffs insist that a literal reading is not enough.
In their view, the Mazars subpoena alters the separation of
powers and raises serious constitutional questions, so nothing
less than an “unequivocal[] grant” by the House of “jurisdiction
to subpoena the President’s accountant for his private financial
records” could authorize the Committee to issue it. Appellants’
Reply Br. 2; see also Dissenting Op. at 52–58. In support, they
raise three related arguments.

     First, the Trump Plaintiffs contend that because “a ‘clear
statement rule’ applies ‘to statutes that significantly alter the
balance between Congress and the President,’” Appellants’ Br.
16 (quoting Armstrong v. Bush, 924 F.2d 282, 289 (D.C. Cir.
1991)), the House could have “authorized the Committee to
embark on [the instant] investigation” only through “an express
statement,” Appellants’ Reply Br. 3 (internal quotation marks
omitted); see also Dissenting Op. at 54–55. For this
proposition, they rely primarily on two decisions, both of
which held that the President is not an “agency” subject to
judicial review under the Administrative Procedure Act (APA).
In the first case, Armstrong v. Bush, our court held that “[w]hen
Congress decides purposefully to enact legislation restricting
or regulating presidential action, it must make its intent clear.”
924 F.2d at 289. “Although the ‘clear statement’ rule was
originally articulated to guide interpretation of statutes that
significantly alter the federal-state balance,” we explained,
“there are similar compelling reasons to apply the rule to
statutes that significantly alter the balance between Congress
and the President.” Id. And in the second case, Franklin v.
                               59
Massachusetts, the Supreme Court confirmed that “[o]ut of
respect for the separation of powers and the unique
constitutional position of the President,” the Court “would
require an express statement by Congress before assuming it
intended the President’s performance of his statutory duties to
be reviewed for abuse of discretion” under the APA. 505 U.S.
788, 800–01 (1992).

      This case is nothing like Armstrong and Franklin for a
simple reason: the House Rules have no effect whatsoever on
“the balance between Congress and the President.” Armstrong,
924 F.2d at 289 (emphasis added). What Rules X and XI have
done is delegate from the House to the Oversight Committee
the authority to exercise Congress’s subpoena power without
first “obtain[ing] such authority . . . by a separate resolution”
of the full House. House Rules and Manual, 115th Cong., § 788
note (2017). The Trump Plaintiffs nowhere dispute that,
assuming a legitimate legislative purpose exists, the House
could have either issued the challenged subpoena by a vote of
the full chamber or, via express statement, authorized the
Committee to issue the subpoena on its behalf. See Oral Arg.
Tr. 5 (conceding that the House has the power to issue the
subpoena itself and arguing that the question is “whether [it]
gave [that authority] to [the] Committee”); id. at 6 (stating that
it is “a question of clarity and not a question of power”); id. at
130–31 (stating that, although it would be “better” for the
subpoena to come from “the full House,” the full House could
pass a rule that “says . . . the committee could do it”). The
Rules, which establish a mechanism for exercising the House’s
subpoena power, thus deal exclusively with the allocation of
authority within the legislative branch, leaving unaltered the
House’s subpoena power vis-à-vis the President. Because
Congress already possesses—in fact, has previously exercised,
see supra at 16–17—the authority to subpoena Presidents and
their information, nothing in the House Rules could in any way
                                60
“alter the balance between” the two political branches of
government. Armstrong, 924 F.2d at 289.

     The Trump Plaintiffs’ second argument, containing many
ingredients of their first, is similarly unavailing. Observing that
“[t]he parties seriously dispute whether the subpoena has a
legitimate legislative purpose,” Appellants’ Reply Br. 3—and,
consequently, whether the subpoena exceeds constitutional
limits on Congress’s subpoena power—the Trump Plaintiffs
urge us to “resolve[] this case in a way that avoid[s] deciding”
constitutional questions “by quashing the subpoena as beyond
the Committee’s . . . jurisdiction,” Appellants’ Br. 23; see also
Department Br. 14; Dissenting Op. at 52–58. They call our
attention to two cases in particular: the Supreme Court’s
decision in United States v. Rumely and ours in Tobin v. United
States, 306 F.2d 270 (D.C. Cir. 1962). In Rumely, the Court
“g[a]ve” the authorizing resolution at issue “a more restricted
scope” because the government’s favored interpretation, which
would have permitted it “to inquire into all efforts of private
individuals to influence public opinion through books and
periodicals,” raised “doubts of constitutionality in view of the
prohibition of the First Amendment” and thus presented a
“[g]rave constitutional question[].” Rumely, 345 U.S. at 46–48.
And in the latter, we “constru[ed] [a] resolution[] of authority
narrowly . . . in order to obviate the necessity of passing on”
the “serious and difficult constitutional question[]” presented
by that case, Tobin, 306 F.2d at 274–75—namely, whether
Congress has “the power, under the compact clause of the
Constitution, to ‘alter, amend or repeal’ its consent to an
interstate compact,” id. at 272. Concerned that “the suspicion
of even potential impermanency would be damaging to the
very concept of interstate compacts,” id. at 273, we observed
that the argument against recognizing such an implied power
to alter or repeal “is not unpersuasive,” id. at 274.
                                61
     In contrast to Rumely and Tobin, the constitutional
questions raised here are neither “[g]rave,” Rumely, 345 U.S.
at 48, nor “serious and difficult,” Tobin, 306 F.2d at 275. We
harbor no doubts that the subpoena to Mazars comports with
constitutional limits, as it seeks documents reasonably relevant
to a legitimate legislative inquiry into “a subject on which
legislation may be had.” Eastland, 421 U.S. at 508; see supra
Parts III.A–C. We therefore have no cause to invoke the canon
of constitutional avoidance. See Empresa Cubana Exportadora
de Alimentos y Productos Varios v. U.S. Department of
Treasury, 638 F.3d 794, 801 (D.C. Cir. 2011) (“A clear statute
and a weak constitutional claim are not a recipe for successful
invocation of the constitutional avoidance canon.”).

     That is not to say the issues presented here are
unimportant—far from it. But the canon of constitutional
avoidance “is not a license for the judiciary to rewrite language
enacted by the legislature.” United States v. Albertini, 472 U.S.
675, 680 (1985). To adopt a restrictive interpretation of the
Rules when uncompelled by constitutional concerns, “while
purporting to be an exercise in judicial restraint,” would in fact
be to “trench upon the legislative powers vested in Congress by
[Article I] of the Constitution.” Id. We have no authority to
avoid questions—even important ones—simply because we
might prefer not to answer them. Cf. United States v. American
Telephone & Telegraph Co., 567 F.2d 121, 126 (D.C. Cir.
1977) (“The simple fact of a conflict between the legislative
and executive branches over a congressional subpoena does not
preclude judicial resolution.”).

     Finally, the Trump Plaintiffs argue that even if no
separation-of-powers concerns demand application of the clear
statement rule, and even if no constitutional questions rise to
the level of serious, it would, given the “sensitive” nature of the
Committee’s request, Appellants’ Reply Br. 2 (internal
                               62
quotation marks omitted), still be “better,” Oral Arg. Tr. 130,
for the full House to grant the Committee “express authority to
subpoena the President for his personal financial records,”
Appellants’ Reply Br. 5. We, however, have no authority to
impose such a requirement on the House. The Constitution
gives “[e]ach House” of Congress authority to “determine the
Rules of its Proceedings,” U.S. Const. art. I, § 5, cl. 2, meaning
that courts lack the power to invalidate a duly authorized
congressional subpoena merely because it might have been
“better [if] . . . the full House” had specifically authorized or
issued it, Oral Arg. Tr. 130. See Eastland, 421 U.S. at 509
(“The wisdom of congressional approach or methodology is
not open to judicial veto.”). To be sure, “the courts will
intervene to protect constitutional rights from infringement by
Congress, including its committees and members.” Exxon
Corp., 589 F.2d at 590. But unless and until Congress adopts a
rule that offends the Constitution, the courts get no vote in how
each chamber chooses to run its internal affairs. See id.
(“[W]here constitutional rights are not violated, there is no
warrant for the judiciary to interfere with the internal
procedures of Congress.”).

     The trouble with clear statement rules, then, is that they
both “involve[] an unwillingness to give full effect to
[Congress’s] unambiguous text” as it exists now, Owner-
Operator Independent Drivers Ass’n v. U.S. Department of
Transportation, 724 F.3d 230, 237 (D.C. Cir. 2013), and offer
a not-so-subtle encouragement to Congress to alter its rules in
the future. Without some constitutionally compelled reason, we
may do neither. As our court recently explained, “interpreting
a congressional rule ‘differently than would the Congress
itself,’ is tantamount to ‘making the Rules—a power that the
Rulemaking Clause reserves to each House alone.’” Barker v.
Conroy, 921 F.3d 1118, 1130 (D.C. Cir. 2019) (quoting United
States v. Rostenkowski, 59 F.3d 1291, 1306–07 (D.C. Cir.
                               63
1995)). Accordingly, absent a substantial constitutional
question pertaining to the House’s legislative power, we have
no more authority to give a cramped interpretation to a House
Rule via a clear statement requirement or the constitutional
avoidance canon than we do to take out our red pens and edit
the Rules ourselves.

     But the House may. And indeed it has. On July 24, several
weeks after oral argument in this case and several months after
the Oversight Committee issued the challenged subpoena to
Mazars, the full House adopted a resolution that in no uncertain
terms “ratifie[d] and affirm[ed]” the Oversight Committee’s
authority under House Rules X and XI to issue subpoenas
“concerning . . . the President in his personal or official
capacity [and] his immediate family, business entities, or
organizations.” H.R. Res. 507, 116th Cong. (2019). Resolution
507—a resolution “[a]ffirming the validity of subpoenas duly
issued and investigations undertaken by . . . committee[s] of
the House . . . pursuant to authorities delegated by . . . the
[House] Rules,” id.—purports neither to enlarge the
Committee’s jurisdiction nor to amend the House Rules.
Instead, the Resolution clarifies the authority that the
Committee had on the day it issued the subpoena. It is “plainly
incorrect,” the Resolution states, to assert that previously
issued subpoenas “seeking personal, financial, banking, and tax
information related to the President” “were not authorized by
the full House.” Id.

     Because the Trump Plaintiffs concede, as they must, that
“[t]he Resolution does not expand the Committee’s
jurisdiction,” Appellants’ July 31 Letter 1; see also Dissenting
Op. at 55 n.18, we need not address their argument that “the
‘scope’ of a committee’s jurisdiction must ‘be ascertained as of
th[e] time’ of the request,” id. (alteration in original) (quoting
Rumely, 345 U.S. at 48). The Trump Plaintiffs may very well
                               64
be right that the authority of a congressional committee to issue
subpoenas “‘cannot be enlarged by subsequent action of
Congress.’” Id. (quoting Rumely, 345 U.S. at 48); but cf.
Dombrowski v. Burbank, 358 F.2d 821, 825 (D.C. Cir. 1966),
aff’d in part, rev’d in part on other grounds sub nom.
Dombrowski v. Eastland, 387 U.S. 82 (1967) (holding that for
purposes of establishing immunity from suit, a subcommittee
could ratify a subpoena previously issued “without prior
authorization from the [s]ubcommittee”). Resolution 507,
however, “enlarges” nothing. It merely confirms what the
Trump Plaintiffs admit—that the plain text of the House Rules
authorizes the subpoena, see supra at 46, and merely provides
what the Trump Plaintiffs request—that the House “‘spell[] out
[its] intention’” by “‘adopt[ing] a resolution which in express
terms authorizes’” the challenged subpoena. Appellants’ Reply
Br. 8–9 (quoting Tobin, 306 F.2d at 275–76). Because the
House has “clearly manifest[ed] its intention of putting such a
decisional burden upon us,” we have no choice but to “meet
and decide” the issues presented by this case. Tobin, 306 F.2d
at 276.

     The Justice Department adds one final objection. Although
conceding that the Resolution “clearly authorizes the
Committee’s subpoena[,]” Department Br. 16, the Department
warns that because Resolution 507 also authorizes future
subpoenas, there is a “serious risk” that “[C]ongressional
committees may issue successive subpoenas in waves, making
far-reaching demands that harry the President and distract his
attention.” Department Br. 6. Time will tell whether the
Department’s prediction is accurate. At present, however, we
have no need to consider that hypothetical scenario because the
only subpoena currently before us is the one directed at Mazars.
And to be clear, neither the Trump Plaintiffs nor the
Department has argued that compliance with that subpoena
risks unconstitutionally burdening the President’s core duties.
                                65

     Nor could they. It is Mazars, a third-party, that will retrieve
and organize the relevant information; the subpoena seeks non-
confidential records in which the President has asserted no
proprietary or evidentiary protections; and Mazars, not the
President, risks contempt through non-compliance. To be sure,
monitoring Mazars’s compliance with the subpoena might
require some presidential time and attention. But as the
Supreme Court made clear in Clinton v. Jones, a “burden [on]
the time and attention of the Chief Executive,” standing alone,
“is not sufficient to establish a violation of the Constitution.”
520 U.S. at 703.

                                V.
     Though our journey has been long, we find ourselves at
the end of a familiar tale. A congressional committee, as
committees have done repeatedly over the past two centuries,
issued an investigative subpoena, and the target of that
subpoena, questioning the committee’s legislative purpose, has
asked a court to invalidate it. The fact that the subpoena in this
case seeks information that concerns the President of the
United States adds a twist, but not a surprising one: disputes
between Congress and the President are a recurring plot in our
national story. And that is precisely what the Framers intended.
As Justice Brandeis wrote, “[t]he doctrine of the separation of
powers was adopted . . . not to promote efficiency but to
preclude the exercise of arbitrary power.” Myers v. United
States, 272 U.S. 52, 293 (1926) (Brandeis, J., dissenting). “The
purpose,” he explained, “was not to avoid friction, but, by
means of the inevitable friction incident to the distribution of
the governmental powers among three departments, to save the
people from autocracy.” Id.

    Having considered the weighty interests at stake in this
case, we conclude that the subpoena issued by the Committee
                           66
to Mazars is valid and enforceable. We affirm the district
court’s judgment in favor of the Oversight Committee and
against the Trump Plaintiffs.

                                               So ordered.
     RAO, Circuit Judge, dissenting: The majority breaks new
ground when it determines Congress is investigating
allegations of illegal conduct against the President, yet
nonetheless upholds the subpoena as part of the legislative
power. The Committee on Oversight and Reform has
consistently maintained that it seeks to determine whether the
President broke the law, but it has not invoked Congress’s
impeachment power to support this subpoena. When Congress
seeks information about the President’s wrongdoing, it does
not matter whether the investigation also has a legislative
purpose. Investigations of impeachable offenses simply are
not, and never have been, within Congress’s legislative power.
Throughout our history, Congress, the President, and the courts
have insisted upon maintaining the separation between the
legislative and impeachment powers of the House and
recognized the gravity and accountability that follow
impeachment. Allowing the Committee to issue this subpoena
for legislative purposes would turn Congress into a roving
inquisition over a co-equal branch of government. I
respectfully dissent.
                               I.
     We are asked to determine whether the Committee’s
subpoena is within the legislative power, a question that raises
serious separation of powers concerns about how a House
committee may investigate a sitting president. The
constitutional questions only hinted at by the majority become
clearer when the proper framework is applied. First, the
Committee’s subpoena and investigation explicitly state a
purpose of investigating illegal conduct of the President,
including specific violations of ethics laws and the
Constitution. Second, Congress’s power to investigate for
legislative purposes, although broad, is not unlimited and
cannot circumvent the distinct power to investigate for
purposes of impeachment. Allegations that an impeachable
official acted unlawfully must be pursued through
impeachment. Finally, the subpoena targets the President and
                               2
raises implications for the separation of powers that the
majority cannot brush aside simply because the subpoena is
addressed to the President’s accountants, Mazars USA, LLP.
These preliminary matters place this novel investigation in
context and frame the analysis of the substantial constitutional
questions presented in this case.
     The Committee, the Trump plaintiffs, and the majority all
agree that the most relevant document for assessing the
Committee’s reasons for issuing the subpoena is Chairman
Elijah E. Cummings’s April 12 Memorandum. See
Memorandum from Chairman Elijah E. Cummings to
Members of the Committee on Oversight and Reform (Apr. 12,
2019) (“Cummings Memorandum”); Appellant Br. 32–33;
Maj. Op. 25; cf. Wilkinson v. United States, 365 U.S. 399, 410
(1961) (looking to the “Chairman’s statement at the opening of
the hearings” for signs of legislative purpose); Shelton v.
United States, 404 F.2d 1292, 1297 (D.C. Cir. 1968). The
Cummings Memorandum states the Committee is investigating
“whether the President may have engaged in illegal conduct”
and notes that this information will “inform[] its review of
multiple laws and legislative proposals under our jurisdiction.”
Cummings Memorandum at 4. The Committee also makes an
“express avowal” to investigate alleged violations of ethics
laws and the Constitution by the President. See McGrain v.
Daugherty, 273 U.S. 135, 178 (1927) (noting that “[a]n express
avowal of the object” of an investigation would aid the courts
in reviewing the Senate’s purpose); see also infra Part III.A
(discussing Committee’s purposes in detail).
     The Committee announces two distinct investigations: one
to explore allegations of illegal conduct by the President; and
another to review multiple laws and legislative proposals
within the Committee’s jurisdiction. The Committee justifies
both inquiries under the legislative power, and the majority
accepts this framework when it examines the legislative power
                                 3
in isolation to determine whether this investigation falls within
its scope. Maj. Op. 20–54. Yet the Constitution vests the House
of Representatives with more than one investigative power.
Most frequently, the House investigates and issues subpoenas
ancillary to its legislative powers. That investigative power is
“co-extensive with the power to legislate.” Quinn v. United
States, 349 U.S. 155, 160 (1955); see also Watkins v. United
States, 354 U.S. 178, 187 (1957) (“The power of the Congress
to conduct investigations is inherent in the legislative process.
That power is broad.”).
     The House, however, has a separate power to investigate
pursuant to impeachment, which has always been understood
as a limited judicial power to hold certain impeachable officials
accountable for wrongdoing. 1 See Kilbourn v. Thompson, 103
U.S. 168, 191 (1880) (“The Senate also exercises the judicial
power of trying impeachments, and the House of preferring
articles of impeachment.”). The text and structure of the
Constitution, its original meaning, and longstanding practice
demonstrate that Congress’s legislative and judicial powers are
distinct and exercised through separate processes, for different
purposes, and with entirely different protections for individuals
targeted for investigation. See infra Part II.


1
  In addition to the legislative and impeachment powers, the House
and the Senate have other investigative powers, not relevant here, to
maintain the integrity of their proceedings and members against
bribery, nuisance, and violence. See Anderson v. Dunn, 19 U.S. (6
Wheat.) 204, 228–30 (1821); Barry v. United States ex rel.
Cunningham, 279 U.S. 597, 613 (1929) (the Senate has “certain
powers, which are not legislative, but judicial, in character. Among
these is the power to judge of the elections, returns, and
qualifications of its own members.” (citing U.S. CONST. art. I, § 5,
cl. 1)).
                                  4
     The Committee’s investigation into alleged illegal actions
of the President naturally raises the specter of impeachment.
Although the Trump plaintiffs maintain that “[t]he one thing
the parties agree on is that this case is not about impeachment,”
Appellants Br. 14, the impeachment power unmistakably sits
in the background of the legal arguments. 2 The Trump
plaintiffs and the Department of Justice have suggested that the
impeachment power might provide a different source of
authority for this subpoena, even though it was not invoked
here. See Appellants Br. 45 (noting with regard to
impeachment that “[w]hile Congress could presumably use
subpoenas to advance these non-legislative powers, the
Committee has not invoked them”); DOJ Br. 15 n.1 (“The
House’s impeachment power is an express authority whose
exercise does not require a connection to valid legislation. But
the Committee has asserted neither jurisdiction over, nor an
objective of pursuing, impeachment.”). Furthermore, one of the
primary legal arguments raised by the Trump plaintiffs is that
the Committee’s investigation is an impermissible form of “law
enforcement.” Appellants Br. 33–37. While law enforcement is
normally the province of the executive branch, the House has a
narrowly circumscribed power to serve as the “NATIONAL
INQUEST” when it acts pursuant to the impeachment power.
The Federalist No. 65, at 338 (Alexander Hamilton) (George
W. Carey & James McClellan eds., 2001). The Committee is

2
  Notably, the district court concluded that the impeachment and
removal powers of the House and the Senate somehow bolster
Congress’s ability to investigate the President through the legislative
power. See Trump v. Comm. on Oversight & Reform, 380 F. Supp.
3d 76, 95 (D.D.C. 2019) (“It is simply not fathomable that a
Constitution that grants Congress the power to remove a President
for reasons including criminal behavior would deny Congress the
power to investigate him for unlawful conduct—past or present—
even without formally opening an impeachment inquiry.”).
                                5
“not here relying on impeachment power.” Oral Arg. at
1:34:19–22. Nevertheless, understanding the impeachment
power is essential to identifying the limits of the legislative
power when Congress seeks to investigate allegations of
specific unlawful actions by the President.
     Constitutional powers do not stand in isolation, but rather
are part of a complex structure in which each power acquires
specific content and meaning in relation to the others. The
Supreme Court often locates the limits of one constitutional
power by identifying what is at the core of another. See, e.g.,
Zivotofsky ex rel. Zivotofsky v. Kerry, 135 S. Ct. 2076, 2096
(2015) (“Congress has substantial authority over passports . . . .
[But] [t]o allow Congress to control the President’s
communication in the context of a formal recognition
determination is to allow Congress to exercise that exclusive
power itself.”); Bowsher v. Synar, 478 U.S. 714, 722 (1986)
(“The Constitution does not contemplate an active role for
Congress in the supervision of officers charged with the
execution of the laws it enacts.”); Youngstown Sheet & Tube
Co. v. Sawyer, 343 U.S. 579, 587 (1952) (“In the framework of
our Constitution, the President’s power to see that the laws are
faithfully executed refutes the idea that he is to be a
lawmaker.”); Myers v. United States, 272 U.S. 52, 164 (1926)
(“[A]rticle 2 excludes the exercise of legislative power by
Congress to provide for appointments and removals, except
only as granted therein to Congress in the matter of inferior
offices.”); Kilbourn, 103 U.S. at 192 (the House “not only
exceeded the limit of its own authority, but assumed a power
which could only be properly exercised by another branch of
the government, because it was in its nature clearly judicial”).
This method helps illuminate the scope of the legislative power
to investigate. Comparing Congress’s legislative power with its
wholly distinct judicial power of impeachment demonstrates
the essential difference between these powers when Congress
seeks to investigate the wrongdoing of the President.
                                  6
     As explained below, allegations of illegal conduct against
the President cannot be investigated by Congress except
through impeachment. The House may impeach for “Treason,
Bribery, or other high Crimes and Misdemeanors,” U.S.
CONST. art. II, § 4, and has substantial discretion to define and
pursue charges of impeachment. See The Federalist No. 65, at
338 (impeachable offenses “are of a nature which may with
peculiar propriety be denominated POLITICAL, as they relate
chiefly to injuries done immediately to the society itself”).
While it is unnecessary here to determine the scope of
impeachable offenses, Congress has frequently treated
violations of statutes or the Constitution as meeting this
threshold. 3 Impeachment provides the exclusive method for
Congress to investigate accusations of illegal conduct by
impeachable officials, particularly with the aid of compulsory
process. 4 Thus, the key determination is whether this

3
 This discussion of the impeachment power proceeds only in relation
to understanding the scope of the legislative power. As the
Committee has not raised the impeachment power as a basis for this
subpoena, questions regarding whether such a subpoena could issue
under the impeachment power are outside the scope of this opinion,
as are other questions regarding the justiciability of the impeachment
power or the specific scope of impeachable offenses. Recognizing
the political nature of impeachable offenses, I refer to them
throughout the opinion by various terms to reflect that such offenses
may include wrongdoing or illegal conduct deemed by the House to
be a high crime or misdemeanor.
4
   Voluntary compliance with congressional investigations is
commonplace. Different concerns arise, however, when one branch
invokes power over the other through compulsory process. See, e.g.,
Watkins, 354 U.S. at 215 (“It is only those investigations that are
conducted by use of compulsory process that give rise to a need to
protect the rights of individuals against illegal encroachment. That
protection can be readily achieved through procedures which prevent
                                7
investigation targets allegations Congress might treat as “high
Crimes” or “Misdemeanors.” To make this determination
requires no search for hidden motives, but simply crediting the
Committee’s consistently stated purpose to investigate “illegal
conduct” of the President. Cummings Memorandum at 4; cf.
Eastland v. United States Servicemen’s Fund, 421 U.S. 491,
508 (1975) (“[I]n determining the legitimacy of a congressional
act we do not look to the motives alleged to have prompted
it.”).
     The Committee’s stated interest in remedial legislation
may support any number of investigations, including into the
conduct of agencies and how officials administer the laws. Yet
a legislative purpose cannot whitewash this subpoena, which—
by the Committee’s own description—targets allegations of
illegal conduct by the President. The most important question
is not whether Congress has put forth some legitimate
legislative purpose, but rather whether Congress is
investigating suspicions of criminality or allegations that the
President violated a law. Such investigations may be pursued
exclusively through impeachment. The House may not use the
legislative power to circumvent the protections and
accountability that accompany the impeachment power.
     The majority recognizes this subpoena concerns the
Committee’s “interest in determining whether and how illegal
conduct has occurred,” Maj. Op. 30, but nonetheless concludes
that it is a valid exercise of the legislative power. This marks a
sharp break with the few judicial precedents in this area. The
Supreme Court has consistently maintained that Congress
cannot undertake a legislative investigation of an impeachable
official if the “gravamen” of the investigation rests on
“suspicions of criminality.” Kilbourn, 103 U.S. at 193, 195. In

the separation of power from responsibility and which provide the
constitutional requisites of fairness for witnesses.”).
                                8
Senate Select Committee on Presidential Campaign Activities
v. Nixon, our court refused to enforce a legislative subpoena to
President Richard Nixon by the Senate Select Committee
tasked with investigating the Watergate break-in. 498 F.2d 725
(D.C. Cir. 1974) (en banc). The tapes sought by the subpoena
were too “tangential” to the Committee’s asserted legislative
purposes, especially because the House had commenced
impeachment proceedings to ascertain the President’s role in
these events. Id. at 733.
       The majority’s holding also breaks with the longstanding
historical practice of Congress and the Executive. Without
analyzing the Constitution or responding to the consistent
historical understanding presented below, the majority simply
asserts that Congress must be able “to make the
quintessentially legislative judgment that some concerns about
potential misconduct or illegality are better addressed through
. . . legislation than impeachment.” Maj. Op. 49. The majority’s
novel holding, however, fails to explain how specific
accusations of wrongdoing by impeachable officials can be
pursued through legislation. The Constitution, historical
practice, and our cases prohibit rolling this investigation of
illegal conduct of the President into a legislative investigation.
Allowing Congress to use the legislative power to circumvent
the impeachment process disrupts the separation of powers. By
simply invoking a need for remedial legislation, Congress may
now expand its control over the other branches and avoid the
accountability and responsibility inherent in the impeachment
power.
     Finally, the inter-branch conflict in this case does not
dissipate simply because the subpoena for the President’s
papers is strategically directed to Mazars rather than the
President. In an attempt to sidestep thorny separation of powers
questions, the majority reduces the conflict to a merely
personal one involving the President’s accountants: “[T]o
                                 9
resolve this case, we need not decide whether the Constitution
permits Congress, in the conduct of a legislative—that is, non-
impeachment—investigation, to issue subpoenas to a sitting
President.” Id. at 20. By the majority’s account, the subpoena
does not transgress any constitutionally prescribed boundaries
between co-equal branches in part because “quite simply, the
Oversight Committee has not subpoenaed President Trump.”
Id. The majority thus concludes that concerns about the relative
powers of the President and Congress do not come into play.
Yet this claim belies both precedent and common sense.
Indeed, by the end of its opinion, the majority abandons even
this reservation and simply asserts, “Congress already
possesses . . . the authority to subpoena Presidents and their
information.” Id. at 59.
     The official actions of the Chief Executive are essentially
bound up in the Mazars subpoena. A subpoena’s force extends
beyond its recipient, which the majority has implicitly
acknowledged by declining to question President Trump’s
standing to challenge the subpoena’s validity. As we have
previously explained: “[T]he fortuity that documents sought by
a congressional subpoena are not in the hands of a party
claiming injury from the subpoena should not immunize that
subpoena from challenge by that party . . . . The fact that the
Executive is not in a position to assert its claim of constitutional
right by refusing to comply with a subpoena does not bar the
challenge.” United States v. AT&T, 567 F.2d 121, 129 (D.C.
Cir. 1977) (citing Eastland, 421 U.S. at 513 (Marshall, J.,
concurring)). Moreover, we have recognized that
congressional subpoenas may create a “portentous clash
between the executive and legislative branches”
notwithstanding the fact that the subpoena was issued against a
private party. United States v. AT&T, 551 F.2d 384, 385 (D.C.
Cir. 1976); accord Eastland, 421 U.S. at 498, 501 n.14
(reviewing challenge to third-party subpoena because
                                 10
otherwise “compliance by the third person could frustrate any
judicial inquiry”).
     The Committee’s subpoena is directed to Mazars but
targets the President’s papers. The form of the subpoena cannot
mask the inter-branch conflict between Congress and the
President. Cf. Judicial Watch, Inc. v. U.S. Secret Serv., 726
F.3d 208, 225–26 (D.C. Cir. 2013) (refusing to allow “end
runs” around “separation-of-powers concerns” by subpoenaing
the Secret Service instead of the President for presidential
calendars). Despite the majority’s skepticism, President Trump
necessarily “carries the mantle of the Office of the President in
this case.” Maj. Op. 24; cf. In re Lindsey, 158 F.3d 1263, 1286
(D.C. Cir. 1998) (Tatel, J., concurring in part and dissenting in
part) (“Because the Presidency is tied so tightly to the persona
of its occupant . . . the line between official and personal can
be both elusive and difficult to discern.”). 5
     The basic contours of the problem are straightforward—
the Committee’s subpoena seeks information regarding alleged
unlawful actions of the President. The direct conflict between
Congress and the President cannot be evaded by treating this as
an ordinary legislative inquiry involving a subpoena to an
accounting firm. In pursuit of remedial legislation, the
Committee may investigate broadly, but this subpoena goes too

5
  As the Department of Justice points out, it is also possible that
judicial resolution would not be necessary if the Committee had
issued the subpoena to the President directly. DOJ Br. 7–8. Instead,
the President and the House would negotiate in the “hurly-burly, the
give and take of the political process between the legislative and the
executive,” likely raising a mix of legal and political arguments and
appealing to the public for support. Executive Privilege - Secrecy in
Government: Hearings Before the Subcomm. on Intergovernmental
Relations of the S. Comm. on Government Operations, 94th Cong.
87 (1975) (statement of Antonin Scalia, Assistant Att’y Gen., Office
of Legal Counsel).
                              11
far because the legislative power cannot target whether the
President violated the law.
                              II.
     The question of whether the House may issue this
subpoena for a legislative purpose presents a serious conflict
between Congress and the President. While the question has
never been squarely addressed by the Supreme Court, Congress
and the executive branch have regularly confronted similar
problems. Accordingly, I start at the beginning. The text and
structure of the Constitution are best read to provide for
impeachment as the exclusive mechanism for reaching the
wrongdoing of the President and other impeachable officials.
The original understanding of Congress’s separate legislative
and impeachment powers, as well as consistent historical
practice since the Founding, confirms that congressional
investigations of the alleged unlawful actions of the President
cannot be pursued through the legislative power. Cf. NLRB v.
Noel Canning, 573 U.S. 513, 524–26 (2014) (“‘[L]ong settled
and established practice is a consideration of great weight in a
proper interpretation of constitutional provisions’ regulating
the relationship between Congress and the President.” (quoting
The Pocket Veto Case, 279 U.S. 655, 689 (1929))).
     Targeting an individual officer for suspicions of
criminality requires proceeding through the impeachment
power, with its attendant procedural protections and
accountability. The majority claims to recount a “familiar tale”
of congressional subpoenas and investigations, Maj. Op. 65;
however, its story covers only legislative investigations that
involve no allegations of wrongdoing against an impeachable
official. The majority’s cursory and selective use of history
glosses over important distinctions carefully maintained by all
three branches between Congress’s legislative and judicial
powers of investigation.
                                12
                                A.
     The text and structure of the Constitution set out with
precision the process for Congress to investigate the unlawful
actions of the President—namely, impeachment by the House
followed by a trial in the Senate. The distinctions between the
legislative and judicial powers of Congress are firmly rooted in
the Constitution and reflect the fundamental differences
between these powers in our system of government. The
original meaning confirms that Congress acts in an exceptional
judicial capacity when exercising impeachment powers.
Investigating unlawful actions by impeachable officials is
outside the legislative power because impeachment provides
the exclusive mechanism for Congress to investigate such
conduct.
     Congress is vested with limited and enumerated legislative
powers, and while the power to investigate is not in the text of
the Constitution, it has long been recognized that Congress may
investigate and issue subpoenas necessary and proper to the
exercise of the legislative power. U.S. CONST. art. I, § 8, cl. 18.
As the Court has explained, “the power of inquiry—with
process to enforce it—is an essential and appropriate auxiliary
to the legislative function.” McGrain, 273 U.S. at 174. Such
investigations are part of the legislative power and may extend
no farther than that power permits. See Quinn, 349 U.S. at 161.
     In the United States, however, the legislative power does
not include the exercise of judicial power to determine the guilt
or innocence of individuals. 6 The Constitution prohibits bills

6
  By contrast, at the time of the Founding, the British House of
Commons possessed broad powers to “impeach” not only officials
but individual citizens, who could be tried by the House of Lords in
a judicial capacity for any criminal offense. 4 William Blackstone,
Commentaries *259–61. As such, Parliament could not only remove
                                 13
of attainder. U.S. CONST. art. I, § 9, cl. 3; art. I, § 10, cl. 1; see
also United States v. Brown, 381 U.S. 437, 442 (1965) (“[T]he
Bill of Attainder Clause was intended not as a narrow, technical
. . . prohibition, but rather as an implementation of the
separation of powers, a general safeguard against legislative
exercise of the judicial function, or more simply—trial by
legislature.”). The Framers understood the importance of
prohibiting Congress from turning its substantial powers
against an individual and possessed a “sense of a sharp
necessity to separate the legislative from the judicial power.”
Plaut v. Spendthrift Farm, Inc., 514 U.S. 211, 219 (1995); see
also Calder v. Bull, 3 U.S. (3 Dall.) 386, 389 (1798) (reviewing
parliamentary abuses of bills of attainder and noting “the
Federal and State Legislatures, were prohibited from passing
any bill of attainder; or any ex post facto law” to prevent “acts
of violence and injustice” against individuals). As
Montesquieu warned, if the judicial powers were “joined with
the legislative, the life and liberty of the subject would be
exposed to arbitrary control; for the judge would then be the
legislator.” Montesquieu, The Spirit of the Laws 157 (A.
Cohler et al. eds., 1989).
     Vested with the power to make the laws, Congress cannot
also execute and adjudicate them. See Fletcher v. Peck, 10 U.S.
(6 Cranch) 87, 136 (1810) (“It is the peculiar province of the
legislature to prescribe general rules for the government of
society; the application of those rules to individuals in society

an official but also assess a broad range of punishments at the
discretion of “the wisdom of the peers.” Id. at *121–22. Against the
abuses of this practice, the Founders limited the scope of
impeachable offenses and punishments for conviction. See Peter
Hoffer & N.E.H. Hull, Impeachment in America, 1635-1805, at 96–
98 (1984); see also Akhil R. Amar, America’s Constitution: A
Biography 199–203 (2005) (describing how the “system of federal
impeachment broke decisively with English impeachment practice”).
                               14
would seem to be the duty of other departments.”). Exercising
the legislative power, Congress may enact general, prospective
rules for the whole of society. Yet Congress cannot prosecute
and decide specific cases against individuals. Such powers
properly belong to the executive branch and the independent
judiciary—a division essential to maintaining fundamental
aspects of our separation of powers and protecting the rights of
individuals accused of illegal actions.
     As an exception to this separation, the Constitution confers
upon the House and Senate limited judicial powers over
impeachable officials. The Constitution vests the House of
Representatives with the “sole Power of Impeachment,” U.S.
CONST. art. I, § 2, cl. 5, and the Senate with the “sole Power to
try all Impeachments,” U.S. CONST. art. I, § 3, cl. 6. The
Constitution creates a two-tier system, dividing limited judicial
power between the House and the Senate to target individual
cases of wrongdoing by impeachable officials. These judicial
powers were understood as exceptions to the legislative power
vested in Congress. See Kilbourn, 103 U.S. at 190–91 (noting
impeachment and removal as exceptions to the separation of
powers because they place judicial power in Congress);
Hayburn’s Case, 2 U.S. (2 Dall.) 408, 410 (1792) (“[N]o
judicial power of any kind appears to be vested [in the
legislature], but the important one relative to impeachments.”).
     In the context of an impeachment inquiry, the House
serves as a kind of grand jury, investigating public officials for
misconduct. As Hamilton noted, the “delicacy and magnitude
of [this] trust” transforms the House into a “NATIONAL
INQUEST.” The Federalist No. 65, at 338. The Senate acts as
a “court for the trial of impeachments,” exercising the “awful
discretion which a court of impeachments must necessarily
have, to doom to honour or to infamy the most confidential and
the most distinguished characters of the community.” Id. at
339. Trial by the Senate in cases of impeachment is part of the
                               15
“judicial character of the Senate.” Id. at 337; see also
Jefferson’s Manual of Parliamentary Practice § 619 (“The trial,
though it varies in external ceremony, yet differs not in
essentials from criminal prosecutions before inferior courts.”).
The Constitution requires senators trying an impeachment to
be on “Oath or Affirmation” and for the Chief Justice to preside
when the President is tried; conviction requires “two thirds of
the Members present.” U.S. CONST. art. I, § 3, cl. 6. The
Constitution refers to “Judgment in Cases of Impeachment.”
U.S. CONST. art. I, § 3, cl. 7.
     As an exercise of judicial power, the impeachment process
targets the individual. The Constitution’s text confirms this
understanding: “no Person shall be convicted,” and “the Party
convicted” shall be liable according to the law. U.S. CONST. art.
I, § 3, cls. 6–7. “The President, Vice President, and all civil
Officers of the United States” are subject to impeachment. U.S.
CONST. art. II, § 4. Article I makes clear that in this role, the
Senate acts as a court trying impeachable offenses and renders
judgment that could result in removal from office and
disqualification from holding any “Office of honor, Trust, or
Profit under the United States.” U.S. CONST. art. I, § 3, cl. 6.
The impeachable offenses enumerated in the Constitution
specifically target individual wrongdoing, namely “Treason,
Bribery, or other high Crimes and Misdemeanors.” U.S.
CONST. art. II, § 4; see also The Federalist No. 65, at 339
(observing the Senate was the only body with “confidence
enough in its own situation, to preserve, unawed and
uninfluenced, the necessary impartiality between an individual
accused, and the representatives of the people, his accusers”).
     The Founders treated impeachable offenses as wholly
distinct from the subjects of investigation for legislative
purposes, such as maladministration. The exact phrasing of an
impeachable offense was debated at the Philadelphia
Convention. After the Convention settled on “Treason, or
                              16
bribery,” George Mason moved to include “maladministration”
as an additional ground for impeachment. 2 Records of the
Federal Convention 550 (Max Farrand ed., 1937). James
Madison objected, arguing that “[s]o vague a term will be
equivalent to a tenure during pleasure of the Senate,” and
Gouverneur Morris argued that “[a]n election of every four
years will prevent maladministration.” Id. Conceding the point,
Mason withdrew “maladministration” and submitted the text
eventually enacted: “other high crimes & misdemeanors.” Id.
Thus, impeachment addresses a public official’s wrongdoing—
treason, bribery, and high crimes or misdemeanors—while
problems of general maladministration are left to the political
process.
     In addition, impeachment by the House and trial by the
Senate were understood to include constitutional rights
normally afforded to the accused in a criminal trial. After
examining English, colonial, and early constitutional practice,
Justice Story concluded that the common law rights of criminal
defendants apply in the exercise of the impeachment power.
See 3 Joseph Story, Commentaries on the Constitution of the
United States § 796 (1833) (“[I]n trials by impeachment the law
differs not in essentials from criminal prosecutions before
inferior courts. The same rules of evidence, the same legal
notions of crimes and punishments prevail.”); see also 3 Asher
C. Hinds, Hinds’ Precedents of the House of Representatives
§ 2486 (“Hinds”) (“In the prosecution of an impeachment, such
rules must be observed as are essential to justice; and, if not
exactly the same as those which are practiced in ordinary
courts, they must be analogous, and as nearly similar to them
as forms will permit.” (quoting Op. Att’y Gen. of May 9,
1796)).
     The Supreme Court has long recognized the enhanced
protections required by impeachment’s judicial function, even
if such matters are generally not justiciable. See Nixon v.
                              17
United States, 506 U.S. 224, 238 (1993) (concluding that
judicial review of impeachment procedures would be
inconsistent with the text and structure of the Constitution);
Marshall v. Gordon, 243 U.S. 521, 547 (1917) (noting that
when the congressional contempt power is “transformed into
judicial authority” as when a “committee contemplate[es]
impeachment,” the authority becomes “subject to all the
restrictions and limitations imposed by the Constitution”);
Kilbourn, 103 U.S. at 190 (impeachment proceedings assume
“the same manner” and employ the “same means that courts of
justice can in like cases”).
    Moreover,      impeachment       and    removal     ensure
accountability to Congress but are not designed to give
Congress direct control over the executive branch. The
President is the head of a co-equal and independent branch of
government. The impeachment power raised concerns for
Gouverneur Morris and other Framers who feared “the
prospect of impeachment would make the chief executive
dependent upon the legislature.” Peter Hoffer & N.E.H. Hull,
Impeachment in America, 1635-1805, at 100 (1984); see also
The Federalist No. 65, at 341 (noting the risk of “persecution
of an intemperate or designing majority in the House of
Representatives”).
     Because of the weighty responsibility of investigating and
trying public officers, “the Constitution structured
impeachment as a system of national accountability.” Akhil R.
Amar, America’s Constitution: A Biography 201 (2005). The
Framers established a mechanism for Congress to hold even the
highest officials accountable, but also required the House to
take responsibility for invoking this power. See 3 Annals of
Cong. 903 (1793) (statement of Rep. Smith) (describing the
“solemnities and guards” the impeachment process offers to
public officers “accused of a breach of duty”); H.R. Rep. No.
93-1305, at 182 (1974) (describing the House’s “responsibility
                               18
as representatives of the people” in the Nixon impeachment
process). By vesting this visible and solemn power in one
institution, the Constitution forces the House to take
accountability for its actions when investigating the President’s
misconduct. See Michael J. Gerhardt, The Federal
Impeachment Process: A Constitutional and Historical
Analysis 110 (1996) (“[M]embers of Congress seeking
reelection have a political incentive to avoid any abuse of the
impeachment power. . . . [T]he cumbersome nature of the
impeachment process makes it difficult for a faction guided by
base personal or partisan motives to impeach and remove
someone from office.”); Julie R. O’Sullivan, The Interaction
Between Impeachment and the Independent Counsel Statute,
86 GEO. L.J. 2193, 2229–30 (1998) (“[E]lectoral accountability
is the ultimate check by which Congress’s abuse of its
otherwise externally unchecked power of impeachment may be
constrained.”).
     In light of the text, structure, and original meaning, the
Constitution is best read to provide for impeachment as the
exclusive mechanism for Congress to investigate the
wrongdoing of the President and other impeachable officials.
See Kendall v. United States ex rel. Stokes, 37 U.S. (12 Pet.)
524, 610 (1838) (“The executive power is vested in a President;
and as far as his powers are derived from the constitution, he is
beyond the reach of any other department, except in the mode
prescribed by the constitution through the impeaching
power.”). It would be wholly inconsistent with this exacting
structure and its explicit safeguards if Congress could target
unlawful actions by impeachable officials simply through its
legislative power, thereby encroaching on the Executive
without the processes, protections, and accountability of
impeachment.
                               B.
                              19
     Because “the interpretive questions before us concern the
allocation of power between two elected branches of
Government,” Noel Canning, 573 U.S. at 524, I proceed to
consider the historical practice regarding congressional
investigations of the executive branch and executive officials.
Cf. Zivotofsky, 135 S. Ct. at 2084 (“To determine whether the
President possesses the exclusive power of recognition the
Court examines the Constitution’s text and structure, as well as
precedent and history bearing on the question.”). While
historical practice is relevant, it does not alter the original
meaning of the Constitution. See McIntyre v. Ohio Elections
Comm’n, 514 U.S. 334, 370 (1995) (Thomas, J., concurring in
the judgment) (recognizing the concern with overturning
longstanding state practice, but concluding that “the historical
evidence from the framing outweighs recent tradition”).
     With respect to Congress’s investigative powers, the
original meaning and historical practice align—all three
branches      have     consistently   distinguished    between
investigations for legislative purposes and investigations
targeting wrongdoing by an impeachable official. Moreover,
the historical evidence demonstrates that Congress often begins
an investigation into the executive branch with general
questions properly pertaining to legislation; however, if an
inquiry turns to suspicions of criminality, Congress moves that
part of the investigation into impeachment or ends the inquiry
into the impeachable official. Thus, even a valid legislative
purpose has never been thought to justify probing specific
accusations of wrongdoing by impeachable officials.
Exercising their independent duty to interpret the Constitution,
the political branches have maintained that impeachment is the
exclusive mechanism for investigating impeachable offenses.
This historical practice reflects and reinforces the
Constitution’s text, structure, and original meaning, and is
consistent with the Supreme Court’s precedents.
                                20
                                1.
     Founding Era practice confirms the Constitution’s original
meaning—investigations of unlawful actions by an
impeachable official cannot proceed through the legislative
power. For instance, in 1793 the House passed a broad
resolution to investigate the administration of the Department
of the Treasury. See 3 Annals of Cong. 835–40 (1793).
Representative William Giles subsequently introduced a string
of resolutions alleging wrongdoing and lawbreaking by
Secretary Alexander Hamilton. Id. at 900 (alleging, inter alia,
“[t]hat the Secretary of the Treasury has violated the law”).
Responding       to    Representative      Giles’s    resolution,
Representative William Smith argued that an investigation of
whether “the Secretary violated a law” could not proceed under
the guise of “an investigation of theoretic principles of
Government.” Id. at 901. Instead, the Constitution “directs”
that Congress must confront “great public functionaries . . .
accused of a breach of duty” through the impeachment process,
with its attendant “solemnities and guards.” Id. at 903; see also
id. at 903–04 (statement of Rep. Murray); id. at 947–48
(statement of Rep. Boudinot) (“[The Committee] were no
longer acting in a Legislative capacity, but were now exercising
the important office of the grand inquest of the Nation . . . . The
honor and reputation of the officer thus charged . . . required a
steady, uniform, and disinterested examination of every
question from us.”). Representative Giles’s resolutions were
decisively defeated. See id. at 955–63.
    Similarly, in 1796 the House requested from President
George      Washington      documents      and      diplomatic
correspondence related to the Jay Treaty and its ratification in
order to determine whether to appropriate the funds necessary
to implement the Treaty. President Washington argued that
because the House could not compel him to disclose the
documents through an exercise of its legislative powers, it
                                21
could demand the documents only through an exercise of its
impeachment power: “It does not occur that the inspection of
the papers asked for can be relative to any purpose under the
cognizance of the House of Representatives, except that of an
impeachment; which the resolution has not expressed.” See 5
Annals of Cong. 760–62 (1796). The House passed a resolution
disapproving of President Washington’s message, but
eventually appropriated the funds necessary to implement the
Treaty without receiving the papers it demanded from the
President. See id. at 1291.
     Moreover, during the early years of the Republic, when the
House sought to target individual, official misconduct, it
proceeded through the impeachment power, not the legislative
power. In the high profile 1805 impeachment of Associate
Justice Samuel Chase, the investigation into his misconduct
proceeded unambiguously under the impeachment power. See
3 Hinds §§ 2342–46. The House specifically defined its role as
that of a grand jury and voted to authorize an impeachment
investigation by a committee vested with subpoena powers. See
id. § 2342. 7
     One early impeachment illustrates the line between
general investigation and impeachment particularly well.
During an investigation of the “disposition of the funds of the
district court,” “the conduct of the judge of the district had been
somewhat implicated.” 32 Annals of Cong. 1715–16 (1818)
(discussing Judge William P. Van Ness of the Southern District
of New York). The Judiciary Committee thought it improper to

7
  Congress conducted such investigations exclusively through the
impeachment power throughout the Founding Era. See 3 Hinds
§§ 2294–2302 (impeachment of Senator William Blount, 1797);
§§ 2319–23 (impeachment of Judge John Pickering, 1803); §§ 2364–
67 (impeachment of Judge James Peck, 1830, highlighting the
importance of protections for the accused before the Senate trial).
                               22
proceed under the existing resolution and sought specific
authority from the House to transfer from a legislative
investigation to an investigation of the judge’s “official
conduct.” Id. After such authority was granted, the Committee
conducted an impeachment inquiry and found no “ground for
the constitutional interposition of the House.” 3 Hinds § 2489.
     Ignoring these Founding Era precedents, the majority
touches briefly on investigations for legislative purposes that
concerned only general maladministration. None of the
majority’s examples involve an allegation of individual
wrongdoing or unlawful activity by an impeachable officer.
Indeed, the majority’s examples help to demonstrate the
original understanding that such investigations proceed
exclusively through the impeachment power.
     The majority begins with the House’s 1792 investigation
into the failure of the expedition under General Arthur St. Clair
in the Northwestern Territory. Maj. Op. 11. This investigation
did not single out any particular officer for misconduct; instead,
it was a general investigation into “the causes of the late defeat
of the army under the command of Major-General St. Clair”
and associated problems of logistics and supply. 3 Hinds
§ 1725. The investigation did not focus on General St. Clair,
who was in any event not an impeachable officer because the
impeachment power extends only to “civil Officers.” U.S.
CONST. art. II, § 4. Rather, the House sought to study the
problems of execution in the expedition as a whole.
Furthermore, at the Washington Administration’s urging,
Congress amended its resolution of inquiry to disclaim any
intention of seeking private papers. See Thomas Jefferson,
Memoranda of Consultations with the President (11 Mar. to 9
Apr. 1792); 3 Hinds § 1726 (calling for papers only “of a public
nature”). Contrast this general investigation with the
investigation of Secretary Hamilton: when the inquiry began to
focus on whether Hamilton had violated the law, the House
                               23
insisted such inquiries could not proceed through the ongoing
legislative investigation. The investigation of the St. Clair
expedition never turned toward an impeachable official, and
therefore remained within Congress’s legislative powers. See 3
Annals of Cong. 490–94 (1792).
     Similarly, the majority’s reference to Congress’s
investigation of the burning of Washington in 1814 offers a
useful example of the line maintained throughout the Founding
Era between general investigation and impeachment. Maj. Op.
12. This legislative investigation focused on the general causes
of the military disaster without targeting any individual officer.
See Herman J. Viola, “The Burning of Washington, 1814,” in
Congress Investigates: A Critical and Documentary History
41–45 (Roger A. Bruns et al. eds., 2011). The majority’s
Founding Era precedents thus buttress the rule that
investigations into the causes of maladministration may
proceed under the legislative power; however, the legislative
power cannot support an investigation into whether an
impeachable official has violated the laws. Such congressional
inquiry must proceed, if at all, through the impeachment
process.
                               2.
     The Founding Era practice continued into the Jacksonian
Era. For example, in 1832, Representative John Quincy Adams
defeated a resolution seeking to conduct a legislative
investigation into charges of public misconduct against a
federal land commissioner. The matter was referred to the
House Judiciary Committee after Adams argued that “[t]he
resolution contained a matter of charge against a public officer.
Prima facie it would lead to an expectation of an impeachment.
It was alike due to the character of the officer in question, and
to the reputation of the House, to investigate the matter
solemnly and effectually.” 8 Reg. Deb. 2198–99 (1832).
                              24
     In 1836, the House appointed a select committee to
conduct a broad investigation of all departments of the Jackson
Administration, empowering the committee to call for persons
and papers. 3 Hinds § 1737. When the Committee’s
investigation focused on particular officials, President Andrew
Jackson intervened in protest of the Committee’s “illegal and
unconstitutional calls for information.” Id. The President
argued that he would fully cooperate with an investigation
conducted “in the accustomed mode,” impeachment, but would
not subject himself to “the establishment of a Spanish
inquisition.” Letter from President Andrew Jackson to Rep.
Henry A. Wise, Chairman, H. Select Comm. (Jan. 26, 1837).
Chairman Wise resisted and submitted a resolution disagreeing
with the doctrine expounded by the President, providing a rare
contrary understanding of the scope of the legislative power to
investigate. But the Chairman’s position was soundly defeated
by his committee, which issued a report endorsing President
Jackson’s position and noting that the investigation amounted
to charges “against the individual officers for ‘corrupt
violation’ of existing laws.” 3 Hinds § 1740. The Committee
further concluded that “the only constitutional power under
which the House of Representatives, as a coordinate branch of
the Government, could constitute a committee to inquire into
alleged ‘corrupt violations of duty’ by another coordinate
branch of the Government (the Executive) is the ‘power of
impeachment.’” Id.
     Indeed, Congress reaffirmed that it could not censure
President Jackson outside the context of impeachment. After
initially voting to censure, the Senate later expunged the
censure from the record on the grounds that “President Jackson
was adjudged and pronounced to be guilty of an impeachable
offence, and a stigma placed upon him, as a violator of his oath
of office, and of the laws and constitution which he was sworn
to preserve, protect, and defend, without going through the
forms of an impeachment, and without allowing him the
                                  25
benefits of a trial, or the means of defence.” 12 Reg. Deb. 878
(1836). 8
     Presidents James Polk, Ulysses Grant, and Grover
Cleveland continued to vigorously defend the line between
legislative and impeachment investigations, maintaining the
latter included legal protections for the officer accused. In
1846, the House formed a select committee to investigate the
possibility of impeaching Daniel Webster, the former Secretary
of State (and then-Senator), with the power to send for papers.
Cong. Globe, 29th Cong., 1st Sess. 945 (1846). While the
Select Committee conducted its investigation, the House
debated a resolution calling for the State Department to
produce documents tending to incriminate Webster. Id. at 636.
Some members argued that only the duly authorized Select
Committee could make such a request. Id. at 636–43.
Representative Adams maintained that an impeachable official
“may not be reached by side-blows.” Id. at 641. The resolution
passed, but President Polk refused to turn over the requested
documents because the resolution did not clearly spell out
8
  The majority asserts that “Presidents, too, have often been the
subject of Congress’s legislative investigations.” Maj. Op. 15. Its one
example from the Jacksonian Era, however, fails to support its
conclusion. The majority refers to the select committee appointed to
investigate former Representative Samuel Houston and whether he
received money from the Secretary of War with the President’s
knowledge. Id. at 15–16. Far from an investigation of the President’s
wrongdoing, this inquiry was part of a broader investigation of
Houston’s assault on a member of Congress for statements made on
the floor. The Committee Report never mentions the President, nor
does it indicate the Committee took any steps to investigate the
President. See 2 Hinds §§ 1616–19; 8 Reg. Deb. 2591–92 (1832)
(context of inquiry); id. at 2595 (then-Rep. Polk proposing inquiry);
id. at 2853 (need for resolution was to determine veracity of
statement made on floor that provoked Houston’s attack); id. at
3022–33 (resolution forming select committee).
                                26
Congress’s intent to obtain the documents pursuant to its
impeachment power.
    President Polk emphasized, however, that he would fully
cooperate with a duly authorized impeachment investigation.
See 2 Hinds § 1561 (“[T]he power of impeachment belongs to
the House of Representatives, and that with a view to the
exercise of this power, that House has the right to investigate
the conduct of all public officers under the government.”
(quoting President James K. Polk, Message to the House of
Representatives, April 20, 1846)). The Select Committee
“entirely concur[red] with the President of the United States”
and his decision not to “communicate or make public, except
with a view to an impeachment” the document sought. Cong.
Globe, 29th Cong. 1st Sess. 946–48, 988 (1846); see also H.R.
Rep. No. 29-684, at 4 (1846). The House approved the Select
Committee’s proposal and took no further action on the matter.
See 2 George Ticknor Curtis, The Life of Daniel Webster 283
(1870). President Polk and the House agreed that the House
may call for documents seeking evidence of a public officer’s
wrongdoing only pursuant to an impeachment investigation. 9
    This issue was raised again by the 1860 House Select
Committee to Investigate Alleged Corruptions in Government
(“Covode Committee”) when it investigated “whether the
President of the United States, or any other officer of the
Government, has, by money, patronage, or other improper
means, sought to influence the action of Congress.”

9
  Presidents adhered to this position throughout the Nineteenth
Century without pushback from Congress. See, e.g., 17 Cong. Rec.
1903 (1886) (statement of President Cleveland) (“I am also led
unequivocally to dispute the right of the Senate, by the aid of any
documents whatever, or in any way save through the judicial process
of trial on impeachment, to review or reverse the acts of the
Executive in the suspension . . . of Federal officials.”).
                              27
2 Hinds § 1596. President Buchanan protested the attempt to
circumvent the impeachment process, noting that while the
House has the “wholesome prerogative” of examining
administration of the departments of the government:
       Should [the House] find reason to believe in the
       course of their examinations that any grave
       offense had been committed by the
       President . . . rendering it proper, in their
       judgment, to resort to impeachment, their
       course would be plain. They would then transfer
       the question from their legislative to their
       accusatory jurisdiction, and take care that . . .
       the accused should enjoy the benefit of cross-
       examining the witnesses and all the other
       safeguards with which the Constitution
       surrounds every American citizen.
President James Buchanan, Addendum to March 28 Message
to Congress (June 22, 1860). The House asserted its power to
investigate generally, but issued no subpoena seeking evidence
of unlawful conduct by the President. See 2 Hinds § 1596; 3
Hinds § 1683.
     Even the Civil War and Reconstruction Congresses, which
strongly asserted congressional power, adhered to the
distinction between investigations for legislative purposes and
investigations of illegal conduct by an impeachable official.
For example, the Joint Committee on the Conduct of the War
harangued non-impeachable military officers and articulated
broad theories of congressional power, but never issued
compulsory process to the President or sought to determine if
particular civil officers violated the law. See generally
Elizabeth Joan Doyle, “The Conduct of the Civil War, 1861–
65” in Congress Investigates at 160–89. The majority’s
reference to the Harpers Ferry investigation, Maj. Op. 12,
similarly misses the mark because that investigation never
                               28
focused on the unlawful conduct of an impeachable official, but
instead sought facts about the raid generally in order to
determine whether legislation was necessary. See Roger A.
Bruns, “John Brown’s Raid on Harpers Ferry, 1859–60” in
Congress Investigates at 127–28.
     The impeachment of President Andrew Johnson
demonstrates the strength of the rule against using legislative
inquiries to circumvent the impeachment process. The House
rebuffed early attempts to initiate an inquiry into President
Johnson’s wrongdoing under the auspices of an investigation
into the executive branch’s administration. See Michael Les
Benedict, “The Impeachment of President Andrew Johnson,
1867–68” in Congress Investigates at 263–64. While a
minority of representatives would have favored using the
legislative power to address President Johnson’s abuses, “the
tedious job of taking testimony and searching through
documents” did not begin until after a formal impeachment
process was initiated. Id.; see also 3 Hinds §§ 2399–2400.
     President Grant maintained the line against aggressive
congressional requests in the midst of Reconstruction. The
House requested detailed information regarding President
Grant’s whereabouts while performing executive functions to
determine whether the President was in violation of the Act of
16 July 1790, which established the District of Columbia as the
seat of government. See 3 Hinds § 1889. President Grant
refused to comply with the request on separation of powers
grounds. See 4 Cong. Rec. 2999–3000 (1876). As he explained,
the investigation did not “belong to the province of legislation,”
nor did it bear on any impeachment proceeding. Id. He
therefore felt obliged under the Constitution to refuse the
request in order to prevent “encroachments upon the proper
powers of the office which the people of the United States have
confided to me.” Id.; see also 3 Hinds § 1889 (“What the House
of Representatives may require as a right in its demand upon
                               29
the Executive for information is limited to what is necessary
for the proper discharge of its powers of legislation or of
impeachment.”). The House took no further action. See 3
Hinds § 1889.
     In the 1879 investigation of United States Consul George
Seward, the House again reaffirmed the separation between
legislative and impeachment investigations. Acting under its
legislative authority, the House Committee on Expenditures in
the State Department attempted to hold Seward in contempt for
failing to comply with a subpoena seeking certain official
papers. Id. § 1699. Seward argued that the Committee was not
authorized to conduct an impeachment inquiry and could not
investigate his alleged misconduct pursuant to the legislative
power. Agreeing with Seward, the House referred the matter to
the Judiciary Committee. Id. The Judiciary Committee’s report
“distinguished[ed] this case from the case of an ordinary
investigation for legislative purposes,” and held that the
Committee on Expenditures had acted beyond its legislative
powers by attempting to circumvent the protections of the
impeachment process:
       The Executive is as independent of either House
       of Congress as either House of Congress is
       independent of him, and they cannot call for the
       records of his action or the action of his officers
       against his consent, any more than he can call
       for any of the journals or records of the House
       or Senate.
Id. §§ 1700, 2514. The Judiciary Committee maintained that
the House had no right to issue compulsory process against the
executive branch outside the impeachment process. 10

10
  The Judiciary Committee recognized that Seward could not be
compelled to produce either private or public papers. His private
                                  30
                                  3.
     Continuing into the Twentieth Century, presidents have
been vigilant against congressional attempts to circumvent the
impeachment process. In 1909, the Senate attempted to
subpoena documents from the Attorney General regarding the
Department of Justice’s failure to act against U.S. Steel
Corporation. President Theodore Roosevelt refused to comply,
so the Senate subpoenaed the Commissioner of Corporations,
an officer within the Department of Commerce and Labor, for
the same documents. See Commissioner of Corporations—
Right of Senate Committee to Ask for Information, 27 Op. Att’y
Gen. 150 (1909). After ordering the Commissioner to withhold
the documents, the President informed the Senate that he would
turn over the documents only if the Senate was acting in its
capacity as an impeachment court. See History of Refusals by
Executive Branch Officials to Provide Information Demanded
by Congress, 6 Op. O.L.C. 751, 769 (1982) (citing Edward S.
Corwin, The President: Office and Powers 429–30 (1957)).
The Senate took no further action. 11
    Investigations of Secretary of the Treasury Andrew
Mellon similarly demonstrate the executive branch’s resistance


papers were protected by the right against self-incrimination and his
title to his private property, which could not be collaterally stripped
by Congress. As for public papers, the Committee recognized them
as within the province of executive privilege. 3 Hinds §§ 1700, 2514.
11
  President Roosevelt’s handling of the matter was recorded by his
personal aide: “I told [Senator Clark] that the Senate should not have
those papers and that [the Commissioner] turned them over to me.
The only way the Senate or the committee can get those papers now
is through my impeachment.” Archibald Willingham Butt &
Lawrence F. Abbott, The Letters of Archie Butt, Personal Aide to
President Roosevelt 305–06 (1924).
                                 31
to releasing documents demanded for legislative purposes in
relation to an impeachable official’s wrongdoing. In 1925,
President Calvin Coolidge refused to hand over Mellon’s tax
returns to a Senate committee tasked with a legislative
investigation of the Bureau of Internal Revenue, noting that
“the attack which is being made on the Treasury Department
goes beyond any . . . legitimate requirements.” 65 Cong. Rec.
6087–88 (1924). 12 In 1929, the Senate Judiciary Committee
investigated Mellon’s alleged violations of financial conflicts
of interest laws. The Committee determined it did not have the
power to issue compulsory process because “it would be a
judicial inquiry and [] not in aid of any legislative function of
the Senate” and could be reached only through “duly instated
criminal proceedings or impeachment proceedings originating
in the House of Representatives.” S. Rep. No. 71-7, at 3 (1929).
In 1932, the House Judiciary Committee was authorized to
conduct a formal impeachment investigation, with subpoena
power, into the same allegations of Mellon’s alleged
lawbreaking. 3 Deschler’s Precedents, Ch. 14, § 14.1
(“Deschler”). 13

12
   Congress did not attempt to enforce the subpoena in court but
instead engaged in negotiations with the executive branch, which
resulted in a compromise and Congress passing legislation regarding
the disclosure of tax returns. See George K. Yin, James Couzens,
Andrew Mellon, the ‘Greatest Tax Suit in the History of the World,’
and Creation of the Joint Committee on Taxation and Its Staff, 66
TAX L. REV. 787, 857 (2013).
13
  The majority’s citation to the Pearl Harbor investigation, Maj. Op.
16, is of limited value, as President Franklin Roosevelt passed away
on April 12, 1945, nearly five months before Congress authorized
the investigation on September 6, 1945, placing the former President
beyond the reach of Congress’s subpoena power. See Wayne
Thompson, “The Pearl Harbor Committee, 1945–46” in Congress
Investigates at 670.
                                 32
                                 4.
     In the modern era, Congress has investigated allegations
of illegal conduct by Presidents Richard Nixon, Ronald
Reagan, and Bill Clinton. The majority cites these as examples
of presidents being “the subject of Congress’s legislative
investigations.” Maj. Op. 16–18. Contrary to the majority’s
characterization, these investigations reinforce that Congress
may launch legislative investigations into administration
generally, including the President’s involvement in
discretionary decisionmaking and purported scandals, but
when wrongdoing by the President is targeted or uncovered the
House transfers allegations of such conduct to an impeachment
inquiry.
     For example, the congressional inquiry into the break-in at
the Democratic National Committee’s headquarters in the
Watergate Hotel began with the creation of a Senate Select
Committee to investigate the incident and determine whether
new legislation on electoral safeguards might be needed. See
S. Res. 60, 93d Cong. § 1(a) (1973). The inquiry centered on
whether any actions—“illegal, improper, or unethical”—took
place, but the inquiry did not target any specific persons. Id.
President Nixon initially rebuffed the Select Committee’s
informal requests for information. See Letter from President
Richard M. Nixon to Sen. Sam J. Ervin Jr., Chairman, Sen.
Select Comm. on Presidential Campaign Activities (July 6,
1973). The Committee, acting pursuant to its legislative power,
later issued two subpoenas to the President. Those subpoenas
were eventually quashed by this court. See Senate Select, 498
F.2d at 733. 14


14
   When the Supreme Court upheld the grand jury request for
President Nixon’s tapes, it specifically confined its decision to the
context of criminal investigations and noted it was not concerned
                              33
     While litigation was pending, the House Judiciary
Committee determined that the evidence gathered through both
the Senate and special counsel investigations had shifted the
focus so heavily toward allegations of wrongdoing by President
Nixon that a formal impeachment investigation was necessary
to proceed any further:
       We have reached the point when it is important
       that the House explicitly confirm our
       responsibility under the Constitution.
       We are asking the House of Representatives, by
       this resolution, to authorize and direct the
       Committee on the Judiciary to investigate the
       conduct of the President of the United States, to
       determine whether or not evidence exists that
       the President is responsible for any acts that in
       the contemplation of the Constitution are
       grounds for impeachment . . . .
       [W]e are asking the House to give the Judiciary
       Committee the power of subpoena in its
       investigations. Such a resolution has always
       been passed by the House. . . . It is a necessary
       step if we are to meet our obligations.
3 Deschler Ch. 14, § 6.2. Only after the House passed a
resolution explicitly invoking its authority under the
impeachment power did the Judiciary Committee subpoena the
President. See H.R. Res. 803, 93d Cong. (1974); H.R. Rep. No.
93-1305, at 6 (1974).
   The House Judiciary Committee took responsibility for
commencing an impeachment investigation and thereafter

with how these issues might be resolved in the context of
“congressional demands for information.” United States v. Nixon,
418 U.S. 683, 712 n.19 (1974).
                                 34
accorded robust procedural protections to ensure that
documents obtained in the course of that process remained
confidential. H.R. Rep. No. 93-1305, at 8–9. The Committee
also determined that the President must comply only with
subpoenas issued “relative to the impeachment inquiry.” 3
Deschler Ch. 14, § 6.12. Notably, one of the grounds in the
resulting articles of impeachment was President Nixon’s
failure to comply with subpoenas, but only those issued after
formal authorization of the impeachment investigation. Id.
§ 15.13. The majority neglects this institutional history and
focuses only on the Select Committee’s unsuccessful attempt
to subpoena the President for legislative purposes. Maj. Op.
17–18. In the 1970s, as in the 1790s, the House recognized the
importance of invoking the impeachment power when an
investigation shifts from a legislative inquiry to an
investigation of the illegal action of an impeachable official.
     Regarding the Iran-Contra Affair in 1987, the majority
asserts that the House committee established to inquire into
illegal arms sales to Iran to finance Nicaraguan rebels sought
to “investigate . . . the role of the President” in those events. Id.
at 16. This misrepresents the broad scope of the investigation,
which inquired into whether and how the National Security
Council staff and other agency officials were involved. The
House resolution forming the Select Committee to Investigate
Covert Arms Transactions with Iran refers to the President only
in relation to assessing the need for legislation regarding
“authorization and supervision or lack thereof of the matters in
this section by the President and other White House personnel.”
H.R. Res. 12, 100th Cong. § 1(e) (1987). The corresponding
Senate resolution does not mention the President at all. See S.
Res. 23, 100th Cong. (1987). Reflecting the general focus on
the process of national security decisionmaking, the joint report
issued by the House and Senate select committees sought to
“explain what happened in the Iran-Contra Affair” rather than
target the actions of any individual official. H.R. Rep. No. 100-
                                35
433, at xv–xvi (1987). The Committees obtained over one
million pages of documents, in part through subpoenas, but
only accessed the President’s personal papers through his
voluntary cooperation.
     Similarly, the majority mischaracterizes the lessons of
Congress’s investigation of the Whitewater Development
Corporation and the eventual impeachment trial of President
Clinton. Congressional involvement began several years after
a United States Attorney forwarded a criminal investigation of
the failure of Madison Guaranty Savings and Loan Association
to the Department of Justice and, ultimately, an independent
counsel. From 1994 to 1998, various House and Senate
committees gathered facts on Madison Guaranty’s failure and
whether agencies and administration officials cooperated with
the independent counsel. See S. Res. 120, 104th Cong. (1995).
The committees investigated with a wide lens, but stopped well
short of targeting offenses by particular officers. See, e.g., S.
Rep. No. 104-191, at 1–3 (1995). Then-Governor Clinton’s
involvement in Whitewater was parsed in relation to public
ethics, good governance, and the regulation of financial
institutions. See The Failure of Madison Guaranty Savings and
Loan Association and Related Matters: Hearing Before the H.
Comm. on Banking and Fin. Servs., 104th Cong. 1–5 (1995)
(opening statement of Rep. James A. Leach, Chairman)
(purpose of Whitewater hearings was to “shed light on the
character of modern political leadership rather than simply
spotlight flaws in a particular leader; . . . [and] to draw lessons
for oversight of our banking laws rather than simply critique
what went wrong with one institution”). While the President
received subpoenas from the independent counsel, other
federal investigators, and a federal grand jury, the majority
points to no examples of either house of Congress issuing a
subpoena to the President prior to impeachment.
                              36
     Once President Clinton’s alleged misconduct became the
target, the House, citing much of the history discussed above,
formally invoked the impeachment power. See H.R. Rep. No.
105-795, at 24 (1998) (“Because impeachment is delegated
solely to the House of Representatives by the Constitution, the
full House of Representatives should be involved in critical
decision making regarding various stages of impeachment.”).
The House proceeded to a full floor vote to authorize an
impeachment inquiry. See H.R. Res. 581, 105th Cong. (1998)
(authorizing the Judiciary Committee to subpoena persons and
things).
     The House also declined to issue a censure resolution
because it would circumvent the Impeachment and Bill of
Attainder Clauses. See H.R. Rep. No. 105-830, at 137 (1998)
(“[F]or the President or any other civil officer, censure as a
shaming punishment by the legislature is precluded by the
Constitution, since the impeachment provisions permit
Congress only to remove an officer . . . and disqualify him from
office. Not only would [censure] undermine the separation of
powers by punishing the President . . . in a manner other than
expressly provided for in the Constitution, but it would violate
the Constitution’s prohibition on Bills of Attainder.”).
                              ***
     The text, structure, and original meaning of the
Constitution are best understood to provide for impeachment
as the exclusive mechanism for Congress to investigate the
illegal conduct of the President and other impeachable
officials. The majority presents no evidence from the
Constitution, our cases, or the consistent interpretation of the
political branches to refute these conclusions. From the
Founding to the present, interactions between the political
branches demonstrate a consistent practice that confirms the
original meaning regarding the separation of the legislative and
judicial powers of the House. The Constitution and our history
                               37
reinforce several principles. First, the House cannot investigate
the illegal conduct of an impeachable officer pursuant to the
legislative power. Second, the investigation of the illegal
conduct of an impeachable officer can be pursued only under
the impeachment power, which transforms the House from a
legislative body into the grand inquest of the nation and affords
procedural and constitutional protections to the accused. Third,
the House may not circumvent the weighty accountability of
the impeachment process simply by proceeding through a
legislative investigation.
                              III.
     With these constitutional and historical principles as
guideposts, I reach the question at hand: whether the
Committee’s subpoena is a valid exercise of the legislative
power. I examine the subpoena and conclude that it seeks to
investigate illegal conduct of the President by reconstructing
past actions in connection with alleged violations of ethics laws
and the Emoluments Clauses. Such an inquiry exceeds
Congress’s legislative power. The remedial legislative
purposes offered by the Committee might authorize any
number of other investigations, but cannot authorize this
subpoena, which seeks to determine whether the President
violated the law. Moreover, this subpoena represents an
unprecedented assertion of legislative power and is readily
distinguished from our previous cases. Neither the
Constitution, nor longstanding interpretation by all three
branches, supports the majority’s conclusion, which upholds—
for the first time—a targeted investigation of the President’s
alleged unlawful conduct under the legislative power.
                               A.
     As the above history makes clear, the House’s legislative
and judicial powers are wholly distinct and the House cannot
target conduct that could constitute a high crime or
                               38
misdemeanor through the legislative power. Discerning the line
between the legislative and impeachment powers does not
require a search for the Committee’s motives because the
Committee has emphasized repeatedly and candidly its interest
in investigating allegations of illegal conduct by the President.
In general, courts properly refrain from questioning legislative
motive when assessing the legitimacy of congressional
investigations, accord Maj. Op. 22, but this does not excuse us
from the judicial duty to assure Congress is acting “in
pursuance of its constitutional power.” Barenblatt v. United
States, 360 U.S. 109, 132 (1959); see also Eastland, 421 U.S.
at 508–09 (upholding subpoenas “about a subject on which
legislation may be had”); Watkins, 354 U.S. at 200 (“[M]otives
alone would not vitiate an investigation . . . if that assembly’s
legislative purpose is being served.”). An inquiry into motive
involves looking behind the stated reasons for a Committee’s
actions. In the Committee’s investigation, however, the
“suspicions of criminality” are quite clearly articulated in the
subpoena, the Cummings Memorandum, and other documents:
the Committee seeks evidence of alleged unlawful actions by
the President. See Shelton, 404 F.2d at 1297 (noting that
sources for determining “[t]he object of the particular inquiry”
include “the resolution of the Congress authorizing the
inquiry,” “the opening statement of the Chairman,” and
“statements of the members of the committee” (citing Watkins,
354 U.S. at 209)); see also Barenblatt, 360 U.S. at 117 (“[T]he
nature of the proceedings themselves, might sometimes make
the topic (under inquiry) clear.” (quoting Watkins, 354 U.S. at
209)).
    First, and most overtly, the subpoena seeks to uncover
“whether the President may have engaged in illegal conduct
before and during his tenure in office.” Cummings
Memorandum at 4. This inquiry relates in part to unofficial
wrongdoing—i.e., events that occurred before President
Trump’s tenure in office—but also to actions during his tenure
                                39
in office. The investigation specifically targets the President. It
is not about administration of the laws generally or the
President’s incidental involvement in or knowledge of any
alleged unlawful activity within the executive branch. Instead
the topics of investigation exclusively focus on the President’s
possible engagement in “illegal conduct.”
     Second, the subpoena seeks to help the Committee
understand “whether [the President] has undisclosed conflicts
of interest that may impair his ability to make impartial policy
decisions.” Id.; see also Appellee Br. 32 (“These documents
may illuminate whether and to what extent [President] Trump
misrepresented his liabilities on federal disclosure forms and
has undisclosed conflicts of interest.”). Again, this inquiry
seeks to uncover alleged wrongdoing—undisclosed conflicts
of interest may violate the statutory reporting requirements
applicable to the President. See Appellee Br. 33 (“[E]xposing
conflicts of interest is one of the core objectives of the Ethics
in Government Act.” (quoting Trump v. Comm. on Oversight
& Reform, 380 F. Supp. 3d 76, 95 (D.D.C. 2019))).
     Third, the subpoena seeks to investigate “whether [the
President] is complying with the Emoluments Clauses of the
Constitution.” Cummings Memorandum at 4; see also
Appellee Br. 34–35 (discussing “[t]he Oversight Committee’s
related investigations into [President] Trump’s potential
violations of the Emoluments Clauses”). On the Committee’s
own terms, it is investigating whether the President is in
violation of the constitutional bar on public officials
“accept[ing] . . . any present, Emolument, Office, or Title.”
U.S. CONST. art. I, § 9, cl. 8 (Foreign Emoluments Clause); see
also U.S. CONST. art. II, § 1, cl. 7 (Domestic Emoluments
Clause). Quite simply the Committee seeks information about
whether the President is violating the Constitution.
    Fourth, the Committee seeks to inquire about “whether
[the President] has accurately reported his finances to the
                               40
Office of Government Ethics and other federal entities.”
Cummings Memorandum at 4; see also Appellee Br. 31 (“[The
Committee’s] investigations include . . . whether [President]
Trump . . . submitted inaccurate financial disclosure forms to
the Ethics Office.”). Again, the Committee seeks to uncover
whether the President has violated the law in his official
capacity—namely, the Ethics in Government Act of 1978, 5
U.S.C. app. 4 § 101 et seq., which imposes financial disclosure
requirements on the President. The Committee’s jurisdiction
includes the authority to conduct oversight of the Office of
Government Ethics and how it implements various ethics
requirements for federal officials. See Letter from Appellee
Regarding Oral Argument Matter at 3–4 (July 16, 2019)
(asserting that the Oversight Committee has jurisdiction over
the Ethics in Government Act under House Rule X, cl. 1(n)(1)).
Yet this particular inquiry is not about the administration of the
Office of Government Ethics or of the laws it administers, but
rather about reconstructing suspected violations of ethics laws
by the Chief Executive. The Committee seeks information
about past transactions related to the President’s financial
reporting—which, if found inaccurate or incomplete, may
carry civil and criminal penalties. See 5 U.S.C. app. 4 § 104(a).
     The four inquiries stated in the Cummings Memorandum
are more than political flourish—they unambiguously set out
the nature of this investigation. These inquiries are repeated
throughout statements and letters of the Chairman on behalf of
the Committee. See, e.g., Letter from Rep. Elijah E.
Cummings, Chairman, H. Comm. on Oversight and Reform, to
Pat Cipollone, Counsel to the President (Jan. 8, 2019) (request
for “documents related to President Trump’s reporting of debts
and payments to his personal attorney, Michael Cohen”); Letter
from Rep. Elijah E. Cummings, Chairman, H. Comm. on
Oversight and Reform, to Emory A. Rounds III, Director of
Office of Gov’t Ethics (Jan. 22, 2019) (request for “documents
relating to President Donald Trump’s reporting of debts and
                                41
payments to his personal attorney, Michael Cohen, to silence
women alleging extramarital affairs”); Letter from Rep. Elijah
E. Cummings, Chairman, H. Comm. on Oversight and Reform,
to Pat Cipollone, Counsel to the President (Feb. 15, 2019)
(demanding answers to “significant questions about why some
of the President’s closest advisors made [] false claims [about
alleged payments] and the extent to which they too were acting
at the direction of, or in coordination with, the President”);
Letter from Rep. Elijah E. Cummings, Chairman, H. Comm.
on Oversight and Reform, to Victor Wahba, Chairman and
Chief Executive Officer, Mazars USA, LLP (Mar. 20, 2019)
(request for documents citing accusation by Cohen that
“President Trump changed the estimated value of his assets and
liabilities on financial statements . . . including inflating or
deflating the value of assets depending on the purpose for
which he intended to use the statements”). The Cummings
Memorandum also relies on the February 27, 2019, hearing
testimony of Michael Cohen, Cummings Memorandum at 1–2,
during which the Chairman and Oversight Committee
members repeatedly invoked allegations of criminality by the
President. See Appellant Br. 7–8 (collecting statements from
Cohen hearing). In this subpoena, the Committee has made
clear that it seeks to investigate illegal conduct of the President.
Indeed, the majority acknowledges that the Committee has an
“interest in determining whether and how illegal conduct has
occurred.” Maj. Op. 30.
     The subpoena itself focuses on information that closely
tracks the Committee’s stated object of investigating illegal
conduct. It seeks, “with respect to Donald J. Trump” and his
organizations, “[a]ll memoranda, notes, and communications”
and “[a]ll underlying, supporting, or source documents and
records” relating to multiple categories of financial statements
going back to 2011, as well as “all engagement agreements or
contracts” “without regard to time.” In addition, the subpoena
specifically demands “all communications” between President
                               42
Trump and his accountants and “all communications related to”
any “potential concerns” that President Trump’s records “were
incomplete, inaccurate, or otherwise unsatisfactory.”
     The subpoena thus seeks to recreate, in exhaustive detail,
the exact processes, discussions, and agreements that went into
preparing the President’s financial records over a multi-year
period in order to determine whether there is anything
misleading or problematic in those records. Such requests are
akin to a criminal grand jury subpoena, designed to “inquire
into all information that might possibly bear on [the]
investigation until it has identified an offense or has satisfied
itself that none has occurred.” United States v. R. Enters., Inc.,
498 U.S. 292, 297 (1991). By contrast, “legislative judgments
normally depend more on the predicted consequences of
proposed legislative actions . . . than on precise reconstruction
of past events.” Senate Select, 498 F.2d at 732.
     Moreover, the Committee’s litigating position in this case
continues to emphasize the importance of the four inquiries,
each of which target the President’s alleged wrongdoing and
potential violations of statutes and the Constitution: “The
Oversight Committee is investigating whether [President]
Trump inaccurately represented liabilities on his statutorily
mandated financial disclosures, impermissibly benefited from
a lease with a government agency, and violated the
Constitution.” Appellee Br. 44; see also id. at 8–17, 21, 22–23,
31–35, 42, 44–45. Thus, we need not peer behind the curtain to
find the Committee’s suspicions of wrongdoing—the
Committee has explicitly and consistently avowed the purpose
of investigating alleged illegal activities of the President.
     The Committee also offers a legislative purpose. The
Cummings Memorandum concludes with the statement that
“[t]he Committee’s interest in these matters informs [the
Committee’s] review of multiple laws and legislative proposals
under [its] jurisdiction.” Cummings Memorandum at 4; see
                                43
also Letter from Rep. Elijah E. Cummings, Chairman, H.
Comm. on Oversight and Reform, to Pat Cipollone, Counsel to
the President (Feb. 15, 2019) (“Congress has investigated how
existing laws are being implemented and whether changes to
the laws are necessary.”). Thus, even though the legislative
purpose appears in a single sentence, the Committee states a
double purpose—to investigate “criminal conduct by
[President] Trump” and also to pursue remedial legislation
relating to government ethics. Appellee Br. 44.
     Given the broad power to investigate in aid of legislation,
remedial legislative purposes will often be sufficient to uphold
an investigation and accompanying subpoena. See Quinn, 349
U.S. at 160–61 (investigative power co-extensive with
legislative power). The majority finds the Committee’s
assertion of a legislative purpose sufficient because “[s]uch an
‘express avowal of the [Committee’s] object’ offers strong
evidence of the Committee’s legislative purpose.” Maj. Op. 26
(quoting McGrain, 273 U.S. at 178). “The Committee’s interest
in alleged misconduct, therefore, is in direct furtherance of its
legislative purpose.” Id. at 31. In other words, the majority
acknowledges that the Committee seeks to investigate illegal
conduct of the President, but then states it is “even more
important” that the Committee is seeking to “review multiple
laws and legislative proposals under [its] jurisdiction.” Id. at 26
(quoting Cummings Memorandum at 4). Because the
Constitution provides only one way for Congress to investigate
illegal conduct by the President, the mere statement of a
legislative purpose is not “more important” when a committee
also plainly states its intent to investigate such conduct. The
legislative power cannot support this subpoena.
     The majority ignores the essential constitutional
distinction between the different investigative powers of
Congress and turns longstanding practice on its head by
concluding dismissively that “we can easily reject the
                               44
suggestion that this rationale [of investigating whether the
‘President may have engaged in illegal conduct’] spoils the
Committee’s otherwise valid legislative inquiry.” Id. at 29. The
valid legislative inquiry is not entirely spoiled—the
Committee’s inquiry into legislative proposals may continue in
any number of legitimate directions. Yet the Committee’s
specific investigation targeting the President, if it is to
continue, may be pursued only through impeachment. Since the
Republic’s beginning, the President, Congress, and the courts
have recognized that when Congress seeks to investigate
individual suspicions of criminality against the President (or
other impeachable officials), it cannot rely on its legislative
powers. The legislative power being more general and
expansive, it cannot trump, so to speak, the more specific
impeachment power, which is necessary for an investigation of
the illegal conduct of the President.
                               B.
     This is the first time a court has recognized that a
congressional investigation pertains to “whether and how
illegal conduct has occurred,” Maj. Op. 30, but then upholds
that investigation under the legislative power. The majority
attempts to rely on our precedents to justify this subpoena by
focusing on whether it is an impermissible exercise of “law
enforcement” power. Id. at 21–22 (responding to appellants).
The majority relies on cases that deal with private citizens and
problems of administration—but a subpoena against the
President that investigates allegations of illegal conduct cannot
be shoehorned into this framework. A review of the cases
demonstrates the novelty of the majority’s holding.
     The majority maintains that “an interest in past illegality
can be wholly consistent with an intent to enact remedial
legislation.” Id. at 29. To the extent the precedents support this
general principle, however, it has been applied only in the
context of private individuals. It is well established that
                                  45
Congress cannot exercise the executive or judicial powers,
which are vested in the other departments of the government.
“[T]he power to investigate must not be confused with any of
the powers of law enforcement; those powers are assigned
under our Constitution to the Executive and the Judiciary.”
Quinn, 349 U.S. at 161. The Court made this general
observation with respect to private individuals, not
impeachable public officials. As far as private individuals are
concerned, Congress emphatically has no law enforcement
powers—no power to indict, to try, or to convict—and cannot
enact a bill of attainder that would single out a person for
punishment through legislation. U.S. CONST. art. I, § 9, cl. 3;
art. I, § 10, cl. 1; see also Brown, 381 U.S. at 445–46 (“[T]he
Legislative Branch is not so well suited as politically
independent judges and juries to the task of ruling upon the
blameworthiness of, and levying appropriate punishment upon,
specific persons. . . . By banning bills of attainder, the Framers
of the Constitution sought to guard against such dangers by
limiting legislatures to the task of rule-making.”).
     The cases cited by the majority demonstrate that during an
investigation of private activity, the incidental revelation of
criminal activity is tolerated when Congress has a legitimate
legislative purpose, 15 precisely because Congress cannot take


15
   Even when a valid legislative purpose exists, the Court has been
vigilant in guarding the constitutional rights of private citizens. See
Watkins, 354 U.S. at 198–99 (courts cannot “abdicate the
responsibility placed by the Constitution upon the judiciary to insure
that the Congress does not unjustifiably encroach upon an
individual’s right to privacy nor abridge his liberty of speech, press,
religion or assembly”); Quinn, 349 U.S. at 161; United States v.
Rumely, 345 U.S. 41, 44 (1953) (“[W]e would have to be that ‘blind’
Court . . . not to know that there is wide concern, both in and out of
Congress, over some aspects of the exercise of the congressional
                               46
any action against a private person for lawbreaking. In
Hutcheson v. United States, the Supreme Court permitted a
Senate committee to investigate the unlawful activity of a
union president despite the fact that, if any wrongdoing was
uncovered, the evidence might have “warranted a separate state
prosecution.” 369 U.S. 599, 617 (1962) (emphasis added). The
union president was, of course, not amenable to prosecution by
Congress. Similarly, in Sinclair v. United States, the Court
allowed a committee to question an oil executive, including on
matters pertaining to pending criminal proceedings involving
that executive. 279 U.S. 263, 290–91, 294–95 (1929). The
proceedings determining the oil executive’s liability or
innocence, however, were being conducted by an entirely
separate branch: the Article III judiciary.
     The Court has upheld some congressional investigations
that incidentally uncover unlawful action by private citizens in
part because private individuals cannot be punished by
Congress, but may be prosecuted by the executive branch and
then face trial before an independent judiciary. Cf. Kilbourn,
103 U.S. at 182 (the Constitution requires that prosecutions of
private individuals proceed by “a trial in which the rights of the
party shall be decided by a tribunal appointed by law, which
tribunal is to be governed by rules of law previously
established”). The majority does not explain why precedents
about union presidents and oil executives would apply to the
President when the Constitution provides a wholly separate
mechanism for Congress to impeach, to try, and, if convicted,
to remove the President from office.
    Importantly, the majority does not cite a single case in
which the Court has upheld a congressional committee’s
investigation into the past illegality of an impeachable official

power of investigation.” (quoting Bailey v. Drexel Furniture Co.,
259 U.S. 20, 37 (1922))).
                               47
for a legislative purpose. In sharp contrast to private
individuals, Congress possesses not only legislative but also
judicial powers over officials amenable to impeachment. This
is a notable and important exception to the separation of
powers—vesting non-legislative powers in the House and
Senate for the limited purpose of checking the actions of certain
high officials. When a legislative investigation turns toward the
wrongdoing of the President or any impeachable official, it has
never been treated as merely incidental to a legislative purpose.
Such investigations require the House to exercise the solemn
powers of the “NATIONAL INQUEST,” The Federalist No.
65, at 338, with all of the procedural protections and
accountability that accompany the decision to target a high
official.
     Indeed, in the one case dealing with a subpoena to the
President for legislative purposes, our court did not ask whether
the Senate Select Committee had a valid legislative purpose in
investigating the events surrounding the Watergate break-in.
See Senate Select, 498 F.2d at 732 (“[T]he need for the tapes
premised solely on [Congress’s] asserted power to investigate
and inform cannot justify enforcement of the [Select]
Committee’s subpoena.”). We concluded instead that a
legislative purpose could not justify demanding the President’s
materials “in the peculiar circumstances of this case, including
the subsequent and on-going investigation of the House
Judiciary Committee.” Id. at 733. As our court explained:
         [T]he House Committee on the Judiciary has
         begun an inquiry into presidential
         impeachment . . . .
         The sufficiency of the [Select] Committee’s
         showing of need has come to depend,
         therefore, entirely on whether the
         subpoenaed materials are critical to the
                               48
         performance of its legislative functions.
         There is a clear difference between
         Congress’s legislative tasks and the
         responsibility of a grand jury, or any
         institution engaged in like functions. While
         fact-finding by a legislative committee is
         undeniably a part of its task, legislative
         judgments normally depend more on the
         predicted consequences of proposed
         legislative actions and their political
         acceptability, than on precise reconstruction
         of past events.
Id. at 732. Thus, we carefully distinguished legislative tasks
from grand jury or similar functions. When the House had
already authorized and was pursuing impeachment
proceedings, we found that the Senate Select Committee’s
legislative need was “too attenuated and too tangential to its
functions to permit a judicial judgment that the President is
required to comply with the Committee’s subpoena.” Id. at 733.
     Similarly here, the questions of illegal conduct and interest
in reconstructing specific financial transactions of the President
are “too attenuated and too tangential” to the Oversight
Committee’s legislative purposes. Id. The parallels between
our case and Senate Select continue to unfold, as some type of
“impeachment inquiry” against the President has been invoked
in the House. See, e.g., Letter from Rep. Adam B. Schiff,
Chairman, H. Perm. Select Comm. on Intelligence et al., to
Rudolph Giuliani (Sept. 30, 2019) (transmitting subpoena for
the President’s papers “[p]ursuant to the House of
Representatives’ impeachment inquiry”).
    Other cases involving congressional investigations of
public officials confirm the distinction between impeachment
and legislative purposes and demonstrate the caution with
which the Court has ensured Congress is not pursuing
                                   49
impeachable offenses in a legislative inquiry. For example, in
McGrain, the Supreme Court upheld an investigation of the
Department of Justice only after determining that there was no
targeted inquiry into unlawful action or allegations of
impeachable offenses. The Senate resolution sought
information about “the administration of the Department of
Justice—whether its functions were being properly discharged
or were being neglected or misdirected, and particularly
whether the Attorney General and his assistants were
performing or neglecting their duties.” McGrain, 273 U.S. at
177. While the resolution mentioned Attorney General
Daugherty, the Court emphasized that the Senate was not
“attempting or intending to try the Attorney General at its bar
or before its committee for any crime or wrongdoing.” Id. at
179–80. It was essential to the Court’s decision that the
investigation did not target the unlawful behavior of the
Attorney General. See id. at 178–80.
     The majority draws a different “lesson” from McGrain:
“that an investigation may properly focus on one individual if
that individual’s conduct offers a valid point of departure for
remedial legislation.” Maj. Op. 31. The majority places
emphasis on the Court’s statement, “[n]or do we think it a valid
objection to the investigation that it might possibly disclose
crime or wrongdoing on [the Attorney General’s] part.”
McGrain, 273 U.S. at 179–80. Yet the Court also stressed that
Congress was not targeting the unlawful behavior of an
impeachable official and that “[i]t is not as if an inadmissible
or unlawful object were affirmatively and definitely avowed.”
Id. at 180. In McGrain, the Court determined that the inquiry
at issue was a legislative one, and specifically did not target
“crime or wrongdoing.” 16 Id. Thus, the majority cannot rely on

16
  The Supreme Court in McGrain did not question the legal principle
articulated by the district court that to investigate the illegal conduct
                                 50
McGrain for its novel holding that Congress can investigate
illegal conduct of an impeachable official pursuant to the
legislative power.
     Similarly, in Kilbourn, the Court invalidated a subpoena
against the Secretary of the Navy because it lacked a legitimate
legislative purpose, while noting that “the whole aspect of the
case would have been changed” if the investigation related to
impeachment. 103 U.S. at 193. No purpose of impeachment
could be found, however, from the preamble characterizing the
Secretary of the Navy’s conduct as “improvident.” Id. The
Court concluded that “the absence of any words implying
suspicion of criminality repel the idea of such [impeachment]
purpose, for the secretary could only be impeached for ‘high
crimes and misdemeanors.’” Id. In McGrain and Kilbourn, the
Court allows Congress some leeway in its legislative
investigations so long as it is not seeking to use the legislative
power to circumvent the impeachment process.
     By contrast, the gravamen of the Oversight Committee’s
investigation in this case is the President’s wrongdoing. The
Committee has “affirmatively and definitely avowed,”
McGrain, 273 U.S. at 180, its suspicions of criminality against
the President. As we recognized in Senate Select, such inquiries
are outside the legislative power in part because they pertain to
subjects proper to an impeachment proceeding in the House,
which like a grand jury must assess whether “certain named

of the Attorney General would be an exercise of the judicial power.
But see Maj. Op. 48 (contending the Supreme Court rejected the
district court’s reasoning in McGrain). Instead, the Supreme Court
simply disagreed with the district court’s characterization of the
proceedings, which were not about the wrongdoing of the Attorney
General but the administration of the Department of Justice as a
whole. “[W]hen the proceedings are rightly interpreted, [ ] the object
of the investigation . . . was to obtain information for legislative
purposes.” McGrain, 273 U.S. at 177.
                                51
individuals did or did not commit specific crimes.” 498 F.2d at
732. The majority’s conclusion is inconsistent with our
precedents, which confirm that investigations of the illegal
conduct of an impeachable official cannot be pursued through
the legislative power.
                               ***
     This subpoena goes beyond the legislative power precisely
because it seeks to reconstruct whether the President broke the
law. The Constitution creates a wholly separate impeachment
power for such inquiries. The majority implicitly collapses
these distinct powers when it concludes that the Committee’s
“interest in determining whether and how illegal conduct has
occurred . . . is in direct furtherance of its legislative purpose.”
Maj. Op. 31. Yet the legislative and impeachment powers are
not interchangeable. Congress, the President, and the courts
have consistently maintained a careful line between these
distinct powers. Thus, I would find that this subpoena exceeds
the legislative power of Congress because it seeks to uncover
wrongdoing by the President.
                                IV.
     By collapsing the distinction between Congress’s
legislative and impeachment powers, the majority’s decision
has serious consequences for the separation of powers. The
decision today expands the legislative power beyond
constitutional boundaries, calling into question our precedents
for reviewing the scope of congressional investigations;
interpreting the legislative power of Congress to subsume the
impeachment power; and permitting serious encroachments on
the executive branch. For the majority, the fact that Congress
seeks the President’s papers is just a “twist” on the history of
congressional investigations. Maj. Op. 65. In our government
of three separate and co-equal departments, the targeting of the
                                  52
President in a congressional subpoena seeking evidence of
illegal conduct is no mere “twist,” but the whole plot.
                                  A.
     At bottom, the majority and I disagree about the meaning
of the legislative power and whether Congress can use this
power to conduct investigations of illegal conduct by the
President. Yet the framework employed by the majority both
decides too little and too much. To begin with, even though the
majority determines that the House has the power to issue this
subpoena, our precedents require making a separate inquiry
regarding the scope of the Committee’s delegated authority. 17
The majority begins by recognizing as much: “it matters not
whether the Constitution would give Congress authority to
issue a subpoena if Congress has given the issuing committee
no such authority.” Maj. Op. 18. The majority, however,
collapses this two-part inquiry by concluding that “[b]ecause
Congress already possesses—in fact, has previously exercised,
see supra at 16–17—the authority to subpoena Presidents and
their information, nothing in the House Rules could in any way
‘alter the balance between’ the two political branches of
government.” Id. at 59–60 (quoting Armstrong v. Bush, 924
F.2d 282, 289 (D.C. Cir. 1991)). The only evidence presented
to support the conclusion that Congress possesses this authority
is a citation to the majority’s analysis—which, as discussed
above, fails to provide a single historical example of a
17
  Because I conclude that Congress lacks the authority to issue this
subpoena pursuant to the legislative power, it follows that the House
could not delegate such authority to the Oversight Committee. See,
e.g., Rumely, 345 U.S. at 42–43 (in assessing validity of
congressional investigation, court must determine “whether
Congress had the power to confer upon the committee the authority
which it claimed”); Kilbourn, 103 U.S. at 196 (committee has “no
lawful authority” to investigate if authorizing resolution is “in excess
of the power conferred on [the House] by the Constitution”).
                               53
successful subpoena to investigate a president for legislative
purposes. Instead, the majority stitches together a few
examples of subpoenas that issued to other officials,
investigations of agency administration, presidents voluntarily
sharing information with Congress, and one case from our
court invalidating the only similar subpoena, which was issued
to President Nixon during the Watergate investigations. Id. at
16–17; see also Senate Select, 498 F.2d at 733. On this flimsy
foundation, the majority concludes that it cannot scrutinize the
House Rules “absent a substantial constitutional question
pertaining to the House’s legislative power.” Maj. Op. 63.
     This conclusion is unsupported by the Supreme Court’s
decisions in this area, which have required courts not only to
consider the scope of legislative power possessed by the House
or Senate as a whole, but to inquire specifically whether that
power has been delegated to a particular Committee. See
United States v. Rumely, 345 U.S. 41, 42–43 (1953) (“This
issue—whether the committee was authorized to exact the
information which the witness withheld—must first be settled
before we may consider whether Congress had the power to
confer upon the committee the authority which it claimed.”);
Watkins, 354 U.S. at 201 (“An essential premise . . . is that the
House or Senate shall have instructed the committee members
on what they are to do with the power delegated to them.”).
This delegation of authority has separate importance because,
as the Court has admonished, Congress should not separate
power from responsibility. Watkins, 354 U.S. at 215.
    The scope of delegation particularly matters when
Congress seeks to investigate a co-equal branch of government.
Requiring a clear statement creates an important form of
accountability by giving notice to the executive branch.
Accordingly, “[w]henever constitutional limits upon the
investigative power of Congress have to be drawn by this
Court, it ought only to be done after Congress has demonstrated
                                   54
its full awareness of what is at stake by unequivocally
authorizing an inquiry of dubious limits.” Rumely, 345 U.S. at
46. We have applied this rule with special force in oversight
investigations: “[T]he courts have adopted the policy of
construing such resolutions of authority narrowly, in order to
obviate the necessity of passing on serious constitutional
questions.” Tobin v. United States, 306 F.2d 270, 274–75 (D.C.
Cir. 1962).
     Moreover, “[o]ut of respect for the separation of powers
and the unique constitutional position of the President,” the
Court requires “an express statement by Congress” before
subjecting the President to legislative restrictions and
oversight. Franklin v. Massachusetts, 505 U.S. 788, 800–01
(1992); see also Armstrong, 924 F.2d at 289. These
longstanding interpretive principles recognize that
congressional encroachments upon the President raise serious
constitutional questions, and courts should not reach out to
decide such questions unless Congress squarely raises the
issue. 18 One might say Congress does not hide presidents in

18
  The ordinary analysis of congressional authorization is somewhat
complicated in this case because, after oral argument, the House
enacted a resolution ratifying “all current and future investigations,
as well as all subpoenas previously issued or to be issued . . . to [inter
alia] the President in his personal or official capacity.” H.R. Res.
507, 116th Cong. (July 24, 2019). The majority, however, does not
rely on this Resolution to provide a clear statement, but merely to
“confirm” the plain meaning of the House Rules, because all the
parties agree that the Resolution does not expand the Committee’s
jurisdiction. Importantly, the majority properly expresses skepticism
and leaves open the question of whether such a resolution can indeed
provide a post hoc expansion of a committee’s subpoena authority.
Maj. Op. 63–64. I similarly decline to speculate about the validity of
a resolution that reaches both forwards and backwards in time to
authorize investigations of the President. See Dombrowski v.
                                 55
mouseholes. Cf. Whitman v. Am. Trucking Ass’ns, Inc., 531
U.S. 457, 468 (2001).
     Thus, even on the majority’s assertion that the House
possesses the legislative power to issue this subpoena, the
Committee might not. The House Rules may upset the balance
of power by failing to provide notice to the President. 19 While
courts should properly refrain from micromanaging the House
Rules, our precedents require reviewing whether Congress has
taken responsibility for pushing up against constitutional
limitations. See Watkins, 354 U.S. at 205–06. In the novel
circumstances of this case, the majority has eviscerated this
longstanding principle and essentially collapsed the broader
question of constitutional power and the question of a
committee’s delegated authority.


Burbank, 358 F.2d 821, 825 (D.C. Cir. 1966) (“Whether this
apparently approving action by the full Subcommittee would serve
as a nunc pro tunc ratification and consequent validation of the
subpoena for all purposes, we need not decide.”), rev’d in part on
other grounds sub nom. Dombrowski v. Eastland, 387 U.S. 82
(1967).
19
   Even without applying the clear statement rule, the majority’s
“natural reading” of the House Rules to include this subpoena is
hardly natural, given that for over 200 years the House has declined
to investigate the wrongdoing of the President without clearly
designating a special committee or resolution for that purpose. That
historical backdrop casts significant doubt on the majority’s
interpretation that a rule making no reference to the President should
be read to encompass the President. See Tobin, 306 F.2d at 275 (“[I]f
Congress had intended the Judiciary Committee to conduct such a
novel investigation it would have spelled out this intention in words
more explicit than the general terms found in the authorizing
resolutions under consideration.”); Barenblatt, 360 U.S. at 117–18
(noting that a vague House rule may acquire content through its
“long history” and the “course of congressional actions”).
                                56
     Another difficulty with the majority’s approach is that it
focuses on the legislative power in isolation, and therefore
proceeds to determine the contours of what legislation could be
had in an area rife with constitutional concerns. See, e.g., Letter
From Laurence H. Silberman, Acting Att’y Gen., to Rep.
Howard W. Cannon, Chairman, H. Comm. on Rules and
Administration 4–5 (Sept. 20, 1974) (construing conflicts of
interest legislation governing the “executive branch” to apply
to the President raises “serious questions of constitutionality”
as such legislation could “disable him from performing some
of the functions required by the Constitution or [] establish a
qualification for his serving as President (to wit, elimination of
financial conflicts) beyond those contained in the
Constitution”). Responding in part to arguments from the
appellants, the majority marches through a very detailed and,
in my view, unnecessary analysis of what specific forms of
legislation might be possible in this area. Maj. Op. 36–45.
     The majority concludes that amendments to “the Ethics in
Government Act . . . to require Presidents and presidential
candidates to file reports more frequently, to include
information covering a longer period of time, or to provide new
kinds of information such as past financial dealings with
foreign businesses or current liabilities of closely held
companies” would pass constitutional muster. Id. at 38–39. The
majority also affirms that some category of theoretical laws
requiring presidents to disclose evidence of potential conflicts
of interest and other financial matters constitute a “less
burdensome species of laws” than similarly hypothetical laws
requiring presidents to divest assets or recuse from conflicted
matters. Id. at 38. Based on this analysis of the relative
constitutionality of as-yet-unenacted laws, the majority
informs us that we can comfortably conclude such financial
disclosure laws of the future would not “prevent[] the
[President] from accomplishing [his] constitutionally assigned
functions.” Id. at 39–40 (alterations in original) (quoting Nixon
                                57
v. Adm’r of Gen. Servs., 433 U.S. 425, 443 (1977)). More
troubling still, the majority declares that a statute “facilitating
the disclosure of” any payment of “foreign emoluments” to the
President would “surely . . . lie[] within constitutional limits,”
id. at 40, notwithstanding the fact that the scope of the Foreign
Emoluments Clause is an unresolved question that is currently
pending before this court. See Blumenthal v. Trump, No. 19-
5237, filed Sept. 4. 2019 (D.C. Cir.). The majority passes on
the constitutionality of a range of different legislative
possibilities without a single enacted statute before us.
     In the absence of any statute that has run the Article I,
section 7, gauntlet, such determinations are advisory at best.
The Article III judicial power extends to deciding cases, not
applying “statutory litmus test[s],” Maj. Op. 37. From the
Founding Era to the present, our courts have refrained from
opining on the constitutionality of legal issues outside of a live
case or controversy. See Chamber of Commerce v. EPA, 642
F.3d 192, 208 (D.C. Cir. 2011) (“To seek judicial review of . . .
a contemplated-but-not-yet-enacted [statute] is to ask the court
for an advisory opinion in connection with an event that may
never come to pass.”); Letter from Chief Justice John Jay and
the Associate Justices of the Supreme Court to President
George Washington (Aug. 8, 1793) (declining the President’s
request to issue an advisory opinion). I would avoid passing on
such questions and simply recognize that an investigation into
the illegal conduct of the President is outside the legislative
power altogether because it belongs to the House’s power of
impeachment for high crimes and misdemeanors.
                                B.
     By allowing the Oversight Committee to use the
legislative power to circumvent the impeachment power, the
majority substantially disrupts the careful balance between
Congress and the other departments. The text and structure of
the Constitution, along with unbroken historical practice, make
                               58
plain the importance of maintaining a line between these
distinct investigative powers—one ancillary to the legislative
power, and the other an exercise of the House’s judicial power
of impeachment. The concerns underlying the distinction are
fundamental and no mere anachronism.
      To begin with, permitting this subpoena allows Congress
to use its substantial legislative power to gather information
that may be used for impeachment without the protections
inherent in an impeachment investigation or proceeding.
Impeachable officials are protected from ill-considered
exercises of this power through careful constitutional design.
The Constitution divides the impeachment and removal powers
between the House and Senate, U.S. CONST. art. I, § 2, cl. 5;
art. I, § 3, cl. 6; limits the scope of impeachable offenses, U.S.
CONST. art. II, § 4; and provides for limited punishments upon
conviction by the Senate, U.S. CONST. art. I, § 3, cl. 7. Senate
trials of impeachment are an exercise of judicial power and
have always been understood to include constitutional and
common law protections similar to what might be available in
the judicial context. Marshall, 243 U.S. at 546–48; Kilbourn,
103 U.S. at 191; Jefferson’s Manual §§ 592, 619 (“The trial . . .
differs not in essentials from criminal prosecutions before
inferior courts.”); 3 Hinds § 2486 (“[S]uch rules must be
observed as are essential to justice.” (quoting Op. Att’y Gen.
of May 9, 1796)); 2 Story § 796 (“[T]he same rules of evidence,
the same legal notions of crimes and punishments prevail.”).
    Allowing the use of legislative power to reach illegal
conduct undermines the protections afforded to officials being
investigated for impeachable offenses. These protections are
essential given the obvious harms to the reputation and honor
of officials targeted through the very public process of
impeachment. See The Federalist No. 65, at 338 (“The delicacy
and magnitude of a trust which so deeply concerns the political
                              59
reputation and existence of every man engaged in the
administration of public affairs, speak for themselves.”).
     Moreover, expanding the legislative power to include
investigations of illegal conduct eviscerates Congress’s
accountability for impeachment. Such accountability is an
essential protection for the People, who elect the President as
well as Members of Congress, and thus have an undeniable
stake in any congressional targeting of the Chief Executive and
his chosen officers. The majority allows Congress to evade
public accountability by permitting investigations of the
President for illegal conduct outside the “grave and weighty”
impeachment process. See Maj. Op. 47. With impeachment, the
Constitution unites power with responsibility. Impeachment
and removal are Congress’s “sword of Damocles,” but the
House and Senate must pay a political price for using these
powers. William H. Rehnquist, Grand Inquests 270 (1992); see
also Gerhardt, The Federal Impeachment Process 57 (“[T]he
framers deliberately made the impeachment process
cumbersome in order to make impeachment difficult to
achieve.”); O’Sullivan, Impeachment and the Independent
Counsel Statute, 86 GEO. L.J. at 2229–30 (“The Framers
intentionally designed the impeachment device to make its
successful invocation difficult in order to ensure that civil
officers would not be unduly dependent upon the legislative
branch.”).
     The House and Senate have consistently maintained the
importance of this responsibility and explicitly invoked the
impeachment power when pursuing official wrongdoing. See,
e.g., 3 Hinds § 2400 (opening Johnson impeachment inquiry);
H.R. Res. 803, 93d Cong. (opening Nixon impeachment
inquiry); H.R. Res. 581, 105th Cong. (opening Clinton
impeachment inquiry). Presidents since George Washington
have declined demands to produce documents for legislative
purposes, while acknowledging that the same request pursuant
                                60
to the impeachment power might be treated differently. See
supra Part II; see also Position of the Executive Department
Regarding Investigative Reports, 40 Op. Att’y Gen. 45, 51
(1941) (Attorney General Robert Jackson declining to provide
information to Congress about pending FBI investigations, but
noting that “pertinent information would be supplied in
impeachment proceedings”). 20
     Overlooking the special procedures and accountability
attendant to an impeachment proceeding, the district court
conflated the legislative and judicial powers of the House. With
no support in the text, structure, or history of the Constitution,
the district court cited the impeachment power to bootstrap a
more expansive legislative power to investigate individual
wrongdoing: “It is simply not fathomable that a Constitution
that grants Congress the power to remove a President for
reasons including criminal behavior would deny Congress the
power to investigate him for unlawful conduct—past or
present—even without formally opening an impeachment
inquiry.” Trump, 380 F. Supp. 3d at 95.
    The district court suggests that the greater power of
impeachment and removal must include the lesser legislative
power to investigate illegal actions by the President. Yet the
Constitution is not designed this way. The greater power does
not include the lesser in a Constitution that explicitly vests
Congress with limited and enumerated legislative powers and


20
   As the Committee has not relied on the impeachment power for
this subpoena, I do not consider whether or how this court would
assess such a demand for documents under the impeachment power.
I simply note that Congress, the Executive, and the courts have
maintained that requests under the legislative and impeachment
powers may be treated differently. See, e.g., Kilbourn, 103 U.S. at
193 (were the investigation related to impeachment, “the whole
aspect of the case would have been changed”).
                               61
then provides for a wholly separate impeachment power with
different objects, processes, and limits. It is not only
fathomable, but essential, that the impeachment and legislative
powers remain distinct. The power of impeachment does not
somehow expand the power to investigate for legislative
purposes.
     The majority similarly recognizes no separation between
the House’s judicial and legislative powers. But once the
boundary between the legislative and judicial powers is
breached, it is hard to discern any limit to the reach of the
legislative power of investigation. Perhaps the functionalist
approach to reading the Constitution has obscured the essential
core of the constitutional powers vested in each of the three
branches. The legislative power focuses on prospective,
general rules for governing society. One thing it has never been
is the power to reconstruct and punish individual actions,
whether of private individuals or public officials. Private and
public individuals are protected by the Bill of Attainder
Clauses, U.S. CONST. art. I, § 9, cl. 3; art. I, § 10, cl. 1, and
Congress may pursue the high crimes and misdemeanors of
impeachable officials exclusively through the impeachment
power, U.S. CONST. art. I, § 2, cl. 5; art. I, § 3, cl. 6.
     Thus, it should be startling when the majority asserts it is
a “quintessentially legislative judgment that some concerns
about potential misconduct are better addressed through . . .
legislation than impeachment.” Maj. Op. 49. The majority
argues in effect that Congress must be able to choose to target
the wrongdoing of the President through its legislative powers,
instead of impeachment. If this does not quite sanction a bill of
attainder, it comes awfully close. The majority’s assertions that
Congress can simply choose between legislation and
impeachment when the President’s wrongdoing is at issue are
unsupported by any constitutional provision and provide no
rebuttal to the remarkably consistent historical understanding,
                                62
which demonstrates that both the executive branch and
Congress, despite their conflicting interests, have steadfastly
maintained the necessity of pursuing wrongdoing of public
officials through impeachment.
     The majority attempts to bolster its argument by
referencing a functional separation of powers and citing to
interpretations of Madison’s statement in Federalist 47 that the
separation of powers “do[es] not mean that these departments
ought to have no partial agency in, or no control over, the acts
of each other.” Id. at 43 (citing Clinton v. Jones, 520 U.S. 681,
702–03 (1997), and Nixon v. Adm’r of Gen. Servs., 433 U.S. at
442–43). Yet Madison’s words are being taken out of context.
In Federalist 47, Madison makes this statement when
interpreting Montesquieu’s theory of separation of powers. See
The Federalist No. 47, at 251 (James Madison). Madison’s
primary point is that “[n]o political truth is certainly of greater
intrinsic value, or is stamped with the authority of more
enlightened patrons of liberty,” than the maxim that “the
legislative, executive, and judiciary departments, ought to be
separate and distinct.” Id. at 249. The general rule of the
Constitution is separation of powers—but the Constitution
includes certain specific exceptions to the general rule, such as
requiring the advice and consent of the Senate in the
appointment of executive officers, or placing the judicial power
of impeachment in the House and Senate. These exceptions
reinforce the system of checks and balances and “provide some
practical security for each, against the invasion of the others.”
The Federalist No. 48, at 256–58 (James Madison). Madison
explains at length the deliberate structure of the Constitution,
which permits overlap or sharing of powers for limited
purposes without collapsing any one branch into dependence
on another.
    The exceptions to the separation of powers, however, have
never been mistaken as a rule of flexible blending of powers
                               63
for the sake of convenience or expediency. To the contrary, the
Court has read the exceptions narrowly and interpreted them to
reinforce the constitutional limits that separate the three powers
of the federal government. See Myers, 272 U.S. at 116 (“[T]he
reasonable construction of the Constitution must be that the
branches should be kept separate in all cases in which they were
not expressly blended, and the Constitution should be
expounded to blend them no more than it affirmatively
requires.”). The majority alleges that this dissent “would
reorder the very structure of the Constitution,” Maj. Op. 49, but
provides no analysis of the Constitution to support its assertion.
Similarly, the majority offers no evidence from the original
meaning, historical practice, or our judicial precedents for its
contrived claim that Congress can simply choose to use either
the legislative or impeachment powers when investigating the
President for violations of the law.
     Instead, the majority chooses to march out a parade of
horribles about what might happen if Congress were unable to
investigate illegal conduct under its legislative power. Id. at
46–47, 48–49. Contrary to the majority’s ahistorical alarm,
maintaining the separation of the legislative and impeachment
powers will in no way prevent the House from continuing to
pursue remedial legislation. I do not question the longstanding
recognition that Congress possesses the ability to investigate as
necessary and proper to effectuate the legislative power. Such
investigations can provide important and salutary oversight of
administration of the laws and study the basis for new
legislation. Yet targeting officials for impeachable offenses
must proceed, and always has proceeded, through the
impeachment power.
    Thus, there is no “Hobson’s Choice” here between
impeachment or nothing, id. at 49, because whether the House
moves forward with impeachment or not, Congress retains all
of the legislative powers it has under the Constitution to
                               64
introduce and enact legislation. The fact that Congress cannot
reconstruct “whether and how” the President violated the law
as part of the legislative power does not “strip[] Congress of its
power to legislate.” Id. Indeed, frustration with lack of access
to documents might prompt Congress to attempt legislation that
requires such disclosure in the future, and similar legislation
has already been proposed. See, e.g., H.R. 1, 116th Cong.,
§§ 8012, 8013 (2019) (increasing stringency of presidential
corporate financial disclosure requirements). To treat an
inquisitorial power as essential to legislation is to
misunderstand the legislative power in the context of our
constitutional system of separated powers. The Committee
cannot use a legislative purpose to circumvent the House’s
power to serve as the grand inquest of the nation when
investigating the illegal conduct of the President.
                               C.
     Allowing the legislative power to reach investigation of
impeachable offenses provides Congress with a new bludgeon
against the Executive, making it all too easy for Congress to
encroach on the executive branch by targeting the President
and his subordinates through legislative inquiries. See Nixon v.
Fitzgerald, 457 U.S. 731, 743 (1982) (a “special solicitude [is]
due to claims alleging a threatened breach of essential
Presidential prerogatives under the separation of powers”). The
majority incorrectly asserts “no party argues that compliance
with the subpoena would impair the President’s execution of
the Article II power.” Maj. Op. 46; see also id. at 64–65. To the
contrary, both the Trump plaintiffs and the Department of
Justice argue that this subpoena may “distract a President from
his public duties, to the detriment of not only the President and
his office but also the Nation that the Presidency was designed
to serve.” Appellants Reply Br. 3 (quoting Fitzgerald, 457 U.S.
at 753); see also DOJ Br. 6 (“[C]ongressional committees may
issue successive subpoenas in waves, making far-reaching
                               65
demands that harry the President and distract his attention.”
(citing Rumely, 345 U.S. at 46)). The majority repeatedly states
that the precedents allow Congress to choose between the
legislative and impeachment powers, but only where “no
intrusion on the President’s execution of his official duties is
alleged.” Maj. Op. 46; see also id. at 45. Yet contrary to the
majority’s assertions, both the Department of Justice and the
President have alleged that the subpoena encroaches on the
executive power, which substantially undermines the
majority’s premise.
     By allowing any claim of a remedial legislative purpose to
justify an investigation into the “illegal conduct” of the
President, the majority effectively expands the already
expansive legislative power. Cf. Brewster v. United States, 255
F.2d 899, 901 (D.C. Cir. 1958) (rejecting an interpretation that
“for all practical purposes, would give the Committee on
Government Operations jurisdiction to investigate virtually
every activity engaged in by every person in the land”).
Pursuant to its legislative powers, Congress already has
substantial leeway to investigate how executive officers are
administering their duties. Yet allowing Congress to use the
legislative power to investigate individual officials for
unlawful conduct takes “oversight” to a whole new level. The
Constitution provides in effect that Congress cannot reach such
allegations by “side-blows,” Cong. Globe, 29th Cong., 1st
Sess. 641 (1846) (statement of Rep. Adams), but must instead
proceed through impeachment. Cf. Morrison v. Olson, 487 U.S.
654, 713 (1988) (Scalia, J., dissenting) (“How much easier it is
for Congress, instead of accepting the political damage
attendant to the commencement of impeachment proceedings
against the President on trivial grounds . . . simply to trigger a
debilitating criminal investigation of the Chief Executive.”).
    Unhindered by the constitutional mechanisms of
accountability, Congress can expand its incursions against the
                                 66
Executive. As Madison cautioned, Congress’s “constitutional
powers being at once more extensive, and less susceptible of
precise limits, it can, with the greater facility, mask under
complicated and indirect measures, the encroachments which
it makes on the co-ordinate departments.” The Federalist No.
48, at 257; see also Zivotofsky, 135 S. Ct. at 2096 (“It was an
improper act for Congress to ‘aggrandize its power at the
expense of another branch.’” (quoting Freytag v. Comm’r, 501
U.S. 868, 878 (1991))).
     The majority takes a narrow view of potential harms to the
executive branch—suggesting that such harms result largely
from the inconvenience of the President having to produce
documents or make copies himself. Maj. Op. 34–35, 65. Yet
using the legislative power to target and uncover illegal
conduct by executive officials provides Congress with an
additional form of control over executive officials who
otherwise must be within the direction and control of the
President. See U.S. CONST. art. II, § 1, cls. 1, 8; art. II, § 3; Free
Enter. Fund v. Pub. Co. Accounting Oversight Bd., 561 U.S.
477, 493 (2010) (invalidating restrictions on the removal power
that would “impair[]” the President’s “ability to execute the
laws [] by holding his subordinates accountable for their
conduct”); Myers, 272 U.S. at 163–64 (“[A]rticle 2 grants to
the President the executive power of the government, i. e., the
general administrative control of those executing the laws.”).
The President cannot “take Care that the Laws be faithfully
executed,” U.S. CONST. art. II, § 3, if his subordinates are
exposed to inquisitorial jeopardy through the ordinary
legislative power.
    Under the majority’s decision, Congress may choose to
launch investigations of illegal conduct under the legislative
power—a choice that under the current rules may be
implemented by a single committee chairman without the
accountability and deliberation that precede impeachment. And
                                 67
while this case deals only with a single subpoena, the
recognition of a wholly unprecedented power to investigate
shifts the balance between the branches and may unleash
additional subpoenas against the President or his subordinates,
which “may, like a flicking left jab, confound the Executive
Branch in dealing with Congress.” In re Sealed Case, 838 F.2d
476, 508 (D.C. Cir. 1988) (Silberman, J.), rev’d sub nom.
Morrison v. Olson, 487 U.S. 654 (1988).
     While congressional oversight investigations may probe a
wide range of matters and often are no picnic for executive
officials, such investigations may proceed ancillary to the
legislative power. Allegations and reconstructions of illegal
conduct, however, are an entirely different matter. If a
congressional committee can invoke a legislative purpose to
subpoena information targeting unlawful actions by the
President, imagine the peril for other officers who lack the
ability to fend off such requests and cannot depend on the
visibility and public mandate that follow the President. Cf.
Morrison, 487 U.S. at 713 (Scalia, J., dissenting) (“[A]s for the
President’s high-level assistants, who typically have no
political base of support, it is [] utterly unrealistic to think that
they will not be intimidated by this prospect [of an independent
counsel], and that their advice to him and their advocacy of his
interests before a hostile Congress will not be affected . . . . It
deeply wounds the President, by substantially reducing the
President’s ability to protect himself and his staff.”). The
prospect of a Congress that can use the legislative power, rather
than impeachment, to reach illegal conduct of executive
officers could very well “weaken the Presidency by reducing
the zeal of his staff.” Id.
                                ***
     Allowing Congress to investigate impeachable officials
for suspicions of criminality pursuant to the legislative power
has serious consequences for the separation of powers because
                               68
it allows Congress to escape the responsibility and
accountability inherent in impeachment proceedings.
Congressional aggrandizement in this case comes at the
expense of the Executive, which no longer can rely on
procedural protections when Congress, or a single committee
chairman, determines to investigate unlawful activity of the
President. The House’s overreaching also comes at the expense
of the People, who established a Constitution with specific
processes for electing both Members of Congress and the
President and which provides only one way for Congress to
punish and remove the President.
                               V.
     The familiar tale recounted by the majority describes a
general arc of expanding legislative powers and the
accompanying recognition of Congress’s power to investigate
ancillary to those powers. Yet the more specific story here
pertains to the fundamental separation between the legislative
and judicial powers of Congress. When the House chooses to
investigate the President for alleged violations of the laws and
the Constitution, it must proceed through impeachment, an
exceptional and solemn exercise of judicial power established
as a separate check on public officials. This constitutional
principle was articulated by George Washington in 1796 and
by the House in 1998: “The Constitution contains a single
procedure for Congress to address the fitness for office of the
President of the United States—impeachment by the House,
and subsequent trial by the Senate.” H.R. Rep. No. 105-830, at
137 (report of the House Judiciary Committee recommending
articles of impeachment).
     The Constitution and our historical practice draw a
consistent line between the legislative and judicial powers of
Congress. The majority crosses this boundary for the first time
by upholding this subpoena investigating the illegal conduct of
the President under the legislative power. I respectfully dissent.
