                FOR PUBLICATION

  UNITED STATES COURT OF APPEALS
       FOR THE NINTH CIRCUIT


UNITED STATES OF AMERICA,                No. 18-16496
               Plaintiff-Appellant,
                                           D.C. No.
                 v.                     2:18-cv-00490-
                                          JAM-KJN
STATE OF CALIFORNIA; GAVIN
NEWSOM, Governor of California;
XAVIER BECERRA, Attorney General           OPINION
of California,
               Defendants-Appellees.



      Appeal from the United States District Court
          for the Eastern District of California
       John A. Mendez, District Judge, Presiding

         Argued and Submitted March 13, 2019
              San Francisco, California

                 Filed April 18, 2019

Before: MILAN D. SMITH, JR., PAUL J. WATFORD,
    and ANDREW D. HURWITZ, Circuit Judges.

         Opinion by Judge Milan D. Smith, Jr.
2          UNITED STATES V. STATE OF CALIFORNIA

                          SUMMARY *


                           Immigration

    In a case in which the United States sought to enjoin the
enforcement of three laws California enacted expressly to
protect its residents from federal immigration enforcement,
the panel affirmed in part and reversed in part the district
court’s denial in large part of the United States’ motion for a
preliminary injunction.

    The United States challenged three California laws:
AB 450, which—as relevant to this appeal—requires
employers to alert employees before federal immigration
inspections; AB 103, which imposes inspection
requirements on facilities that house civil immigration
detainees; and SB 54, which limits the cooperation between
state and local law enforcement and federal immigration
authorities.

    The United States sought a preliminary injunction,
arguing that these laws violated the doctrine of
intergovernmental immunity and the doctrine of conflict
preemption. The district court concluded that the United
States was unlikely to succeed on the merits of many of its
claims, and so denied in large part the motion for a
preliminary injunction.

    With respect to AB 450, which requires employers to
alert employees before federal immigration inspections, the
panel affirmed the district court’s denial of a preliminary

    * This summary constitutes no part of the opinion of the court. It
has been prepared by court staff for the convenience of the reader.
         UNITED STATES V. STATE OF CALIFORNIA                3

injunction. The panel rejected the United States’ contention
that the provisions are invalid under the doctrine of
intergovernmental immunity and the doctrine of conflict
preemption, concluding that the district court did not abuse
its discretion when it concluded that AB 450’s employee-
notice provisions neither burden the federal government nor
conflict with federal activities.

    With respect to AB 103, which imposes inspection
requirements on facilities that house civil immigration
detainees, the panel affirmed the denial of a preliminary
injunction as to those provisions of AB 103 that duplicate
inspection requirements otherwise mandated under
California law and are imposed on state and local detention
facilities.

    However, the panel concluded that one subsection of
AB 103—California          Government       Code       section
12532(b)(1)(C), which requires examination of the
circumstances surrounding the apprehension and transfer of
immigration       detainees—discriminates      against      and
impermissibly burdens the federal government, and so is
unlawful under the doctrine of intergovernmental immunity.
Specifically, the panel concluded that the district court erred
by relying on a de minimis exception to the doctrine of
intergovernmental immunity in analyzing this provision.
The panel concluded that Supreme Court case law compels
the rejection of such a de minimis exception and held that
any economic burden that is discriminatorily imposed on the
federal government is unlawful. The panel also concluded
that the district court was incorrect in concluding that the
review required by the provision appeared no more
burdensome than reviews required under other California
provisions. Therefore, the panel reversed the district court’s
4        UNITED STATES V. STATE OF CALIFORNIA

denial of a preliminary injunction as to California
Government Code section 12532(b)(1)(C).

    With respect to SB 54, which limits the cooperation
between state and local law enforcement and federal
immigration authorities, the panel affirmed the district
court’s denial of a preliminary injunction. The panel
rejected the United States’ argument that the provisions
violate the doctrine of obstacle preemption and the doctrine
of intergovernmental immunity, concluding that the district
court did not abuse its discretion when it concluded that that
any obstruction caused by SB 54 is consistent with
California’s prerogatives under the Tenth Amendment and
the anticommandeering rule.

    The panel also rejected the United States’ contention that
SB 54’s information-sharing restrictions—which prohibit
state and local law enforcement agencies from providing
information regarding a person’s release date from
incarceration or other personal information—conflict with
8 U.S.C. § 1373, which provides that “a Federal, State, or
local government entity or official may not prohibit, or in
any way restrict, any government entity or official from
sending to, or receiving from, [the Department of Homeland
Security] information regarding the citizenship or
immigration status, lawful or unlawful, of any individual.”
Although SB 54 expressly permits the sharing of information
about immigration status, the United States argued that
section 1373 actually applies to more information than just
immigration status, and hence that SB 54’s prohibition on
sharing other information created a direct conflict. The
panel disagreed, explaining that the language of section 1373
is naturally understood as a reference to a person’s legal
classification under federal law.
         UNITED STATES V. STATE OF CALIFORNIA                5

    Finally, the panel addressed California’s argument that
the three other factors for determining whether to issue a
preliminary injunction—irreparable harm, the balance of the
equities, and the public interest—provide an alternative basis
for affirming the district court’s denial of a preliminary
injunction. Because the panel concluded that the United
States is unlikely to succeed on the merits of its challenges
to AB 450 and SB 54, the panel considered these factors only
as applied to the provision of AB 103 that imposes an
impermissible burden on the federal government. The panel
concluded it was not prepared, in the first instance, to affirm
the district court’s denial of a preliminary injunction as to
this provision based on equitable considerations. However,
the panel encouraged the district court, on remand, to
reexamine the equitable factors in light of the evidence in the
record.


                         COUNSEL

Daniel Tenny (argued), Brad Hinshelwood, Laura Myron,
Katherine Twomey Allen, Daniel Tenny, and Mark B. Stern,
Appelate Staff; Hashim M. Mooppan, Deputy Assistant
Attorney General; McGregor Scott, United States Attorney;
Joseph H. Hunt, Assistant Attorney General; Civil Division,
United States Department of Justice, Washington, D.C.;
Joshua S. Press, Francesca Genova, Joseph A. Darrow, and
Lauren C. Bingham, Trial Attorneys; Erez Reuveni,
Assistant Director; August Flentje, Special Counsel; Office
of Immigration Litigation, Civil Division, United States
Department of Justice, Washington, D.C.; for Plaintiff-
Appellant.

Aimee Feinberg (argued), Deputy Solicitor General; Kristin
Liska, Associate Deputy Solicitor General; Lee I. Sherman,
6        UNITED STATES V. STATE OF CALIFORNIA

Maureen C. Onyeagbako, and Cherokii DM Melton, Deputy
Attorneys General; Christine Chuang, Anthony Hakl, and
Satoshi Yanai, Supervising Deputy Attorneys General;
Thomas S. Patterson, Senior Assistant Attorney General;
Edward C. DuMont, Solicitor General; Xavier Becerra,
Attorney General; Office of the Attorney General,
Sacramento, California; for Defendants-Appellees.

David L. Caceres, Assistant City Attorney; Lonnie J.
Eldridge, City Attorney; Office of the City Attorney, Simi
Valley, California; for Amicus Curiae City of Simi Valley.

Anthony S. Chavez, Daniel L. Richards, and Matthew E.
Richardson, Best Best & Krieger LLP, Irvine, California, for
Amicus Curiae City of Lake Forest.

Christopher J. Hajec, Elizabeth A. Hohenstein, and Mark S.
Venezia, Immigration Reform Law Institute, Washington,
D.C., for Amici Curiae National Law Enforcement
Associations and Victims’ Organizations.

Kyle D. Hawkins, Solicitor General; Ari Cuenin and Eric A.
White, Assistant Solicitors General; Jeffrey C. Mateer, First
Assistant Attorney General; Ken Paxton, Attorney General;
Office of the Attorney General, Austin, Texas; for Amici
Curiae States of Texas, Alabama, Arkansas, Florida,
Georgia, Indiana, Kansas, Louisiana, Nebraska, Nevada,
Ohio, Oklahoma, South Carolina, West Virginia, and
Governor Phil Bryant of the State of Mississippi.

Lawrence J. Joseph, Law Office of Lawrence J. Joseph,
Washington, D.C.; Sarah R. Rehlberg and Dale L. Wilcox,
Immigration Reform Law Institute, Washington, D.C.; for
Amici Curiae Municipalities and Elected Officials.
         UNITED STATES V. STATE OF CALIFORNIA             7

John P. Cooley, Senior Deputy County Counsel; Thomas E.
Montgomery, County Counsel; Office of County Counsel,
San Diego, California; for Amicus Curiae County of San
Diego.

Sara J. Eisenberg, Aileen M. McGrath, and Tara M. Steeley,
Deputy City Attorneys; Yvonne R. Mere, Chief of Complex
and Affirmative Litigation; Ronald P. Flynn, Chief Deputy
City Attorney; Jesse C. Smith, Chief Assistant City
Attorney; Dennis J. Herrera, City Attorney; Office of the
City Attorney, San Francisco, California; for Amicus Curiae
City and County of San Francisco.

Benjamin G. Shatz, Michael G. Nordon, and Esra A.
Hudson, Manatt Phelps & Phillips LLP, Los Angeles,
California, for Amici Curiae Faith-Based Organizations.

Harit U. Trivedi, Strefan Fauble, Valerie L. Flores, Deputy
City Attorneys; James P. Clark, Chief Deputy City
Attorneys; Leela A. Kapur, Chief of Staff; Michael N. Feuer,
City Attorney; Office of the City Attorney, Los Angeles,
California; for Amicus Curiae City of Los Angeles.

David M. Zionts, Ivano M. Ventresca, and Eric H. Holder
Jr., Covington & Burling LLP, Washington, D.C.; Jessica R.
Hanson and Daniel N. Shallman, Covington & Burling LLP,
Los Angeles, California; for Amicus Curiae California State
Senate.

Matthew J. Piers, Caryn C. Lederer, and Chirag G. Badlani,
Hughes Socol Piers Resnick & Dym Ltd., Chicago, Illinois;

Daniel B. Rice, Joshua A. Geltzer, and Mary B. McCord,
Institute for Constitutional Advocacy and Protection,
8        UNITED STATES V. STATE OF CALIFORNIA

Washington, D.C.; for Amici Curiae Current and Former
Prosecutors and Law Enforcement Leaders.

Fredrick S. Levin, Daniel R. Paluch, Ali M. Abughedia, and
Michael A. Rome, Santa Monica, California, for Amicus
Curiae American Jewish Committee.

Bradley S. Phillips and Gregory D. Phillips, Munger Tolles
& Olson LLP, Los Angeles, California, for Amici Curiae
Immigration, Labor and Employment Law Scholars re:
AB 450.

Harry Sandick and Michael D. Schwartz, Patterson Belknap
Webb & Tyler LLP, New York, New York; Kevin A. Calla,
Law Office of Kevin A. Calla, Roseville, California; for
Amici Curiae Administrative Law, Constitutional Law,
Criminal Law and Immigration Law Scholars.

Margaret L. Carter and Daniel R. Suvor, O’Melveny &
Myers LLP, Los Angeles, California; Erin Bernstein and
Malia McPherson, Deputy City Attorneys, Maria Bee, Chief
Assistant City Attorney; Barbara J. Parker, City Attorney;
Office of the City Attorney, Oakland, California; Javier
Serrano, Deputy County Counsel; Kavita Narayan, Lead
Deputy County Counsel; Greta S. Hansen, Chief Assistant
County Counsel; James R. Williams, County Counsel;
Office of the County Counsel, San Jose, California; for
Amici Curiae 29 California Counties, Cities, and Local
Officials.

Abigail K. Coursolle, Ian McDonald, Joe McLean, and
Sarah Grusin, National Health Law Program, Los Angeles,
California, for Amici Curiae National Health Law Program,
Asian Law Alliance; Bay Area Lawyers for Individual
Freedom; California Center for Rural Policy; California
         UNITED STATES V. STATE OF CALIFORNIA           9

National Organization for Women; Center for Civil Justice;
Center for Medicare Advocacy, Inc.; Citizens for Choice;
Community Legal Aid Society, Inc.; Congregation of Our
Lady of Charity of the Good Shepherd, US Provinces;
CWDA; Desert AIDS Project; Disability Rights California;
Disability Rights Education and Defense Fund; Disability
Rights Legal Center; Equality California; Florida Legal
Services, Inc.; In Our Own Voice: National Black Women's
Reproductive Justice Agenda; Kentucky Equal Justice
Center; Legal Aid Justice Center; Legal Aid Society of San
Mateo County; Legal Council for Health Justice; Maternal
and Child Health Access; Medical Students for Choice;
National Asian Pacific American Families Against
Substance Abuse; NARAL Pro-Choice California; National
Asian Pacific American Women's Forum; National Center
for Law and Economic Justice; National Hispanic Medical
Association; National Institute for Reproductive Health;
National Organization for Women Foundation; National
Women's Law Center; Northwest Health Law Advocates;
Physicians for Reproductive Health; Planned Parenthood
Affiliates of California; Positive Women's Network – USA;
Public Justice Center; The Children's Partnership; The New
York Immigration Coalition; The Praxis Project; The
Sargent Shriver National Center on Poverty Law; The
Southwest Women's Law Center; and Western Center on
Law & Poverty.

MacKenzie Fillow, John Moore, Noah Kazis, Aaron Bloom,
and Richard Dearing, Of Counsel; Zachary W. Carter,
Corporation Counsel; New York City Law Department,
New York, New York, for Amici Curiae City of New York
and 21 Local Governments.
10       UNITED STATES V. STATE OF CALIFORNIA

                         OPINION

M. SMITH, Circuit Judge:

    Defendant-Appellee State of California (California)
enacted three laws expressly designed to protect its residents
from federal immigration enforcement: AB 450, which
requires employers to alert employees before federal
immigration inspections; AB 103, which imposes inspection
requirements on facilities that house civil immigration
detainees; and SB 54, which limits the cooperation between
state and local law enforcement and federal immigration
authorities. Plaintiff-Appellant United States of America
(the United States) challenged these enactments under the
Supremacy Clause and moved to enjoin their enforcement.
The district court concluded that the United States was
unlikely to succeed on the merits of many of its claims, and
so denied in large part the motion for a preliminary
injunction.

    The district court did not abuse its discretion when it
concluded that AB 450’s employee-notice provisions neither
burden the federal government nor conflict with federal
activities, and that any obstruction caused by SB 54 is
consistent with California’s prerogatives under the Tenth
Amendment and the anticommandeering rule. We therefore
affirm the district court’s denial of a preliminary injunction
as to these laws. We also affirm the denial of a preliminary
injunction as to those provisions of AB 103 that duplicate
inspection requirements otherwise mandated under
California law. But we conclude that one subsection of AB
103—codified at California Government Code section
12532(b)(1)(C)—discriminates against and impermissibly
burdens the federal government, and so is unlawful under the
doctrine of intergovernmental immunity. Because the
         UNITED STATES V. STATE OF CALIFORNIA               11

district court relied on incorrect law in analyzing this
provision, we reverse its preliminary injunction order in part.

  FACTUAL AND PROCEDURAL BACKGROUND

I. Factual Background

    We first review the relevant federal statutory framework
before describing the three California laws at issue in this
case.

   A. Federal Statutory Framework

       i. The INA

     “The Government of the United States has broad,
undoubted power over the subject of immigration and the
status of aliens.” Arizona v. United States (Arizona II),
567 U.S. 387, 394 (2012); see also U.S. Const. art. I, § 8,
cl. 4 (granting Congress the power to “establish an uniform
Rule of Naturalization”); United States v. Curtiss-Wright
Exp. Corp., 299 U.S. 304, 315–18 (1936) (exploring the
federal government’s inherent sovereign powers in the realm
of foreign affairs). Congress exercises its authority to
regulate the entry, presence, and removal of noncitizens
through the Immigration and Nationality Act (INA) and
other related laws, and “has specified which aliens may be
removed from the United States and the procedures for doing
so.” Arizona II, 567 U.S. at 396. “A principal feature of the
removal system is the broad discretion exercised by
immigration officials.” Id. For example, “an alien may be
arrested and detained pending a decision on whether the
alien is to be removed from the United States,” and until that
decision, federal officials generally may either detain her or
release her on bond. 8 U.S.C. § 1226(a). Detention is
mandatory, however, for certain categories of noncitizens,
12        UNITED STATES V. STATE OF CALIFORNIA

including those who are inadmissible or removable due to
criminal convictions. Id. § 1226(c).

    “The Attorney General shall arrange for appropriate
places of detention for aliens detained pending removal or a
decision on removal,” which might include the “purchase or
lease of [an] existing prison, jail, detention center, or other
comparable facility suitable for such use.” Id. § 1231(g); see
also id. § 1103(a)(11) (permitting agreements with states
and localities “for the necessary construction, physical
renovation, acquisition of equipment, supplies or materials
required to establish acceptable conditions of confinement
and detention”).       The United States notes that the
Department of Homeland Security (DHS) “regularly uses
nine facilities in California to house civil immigration
detainees,” which collectively have a capacity of
approximately 5,700 detainees. The interplay between
federal and state authorities also manifests itself when
noncitizens subject to removal are also the targets of state or
local criminal enforcement. The INA requires that DHS
remove an alien who is subject to a final removal order
“within a period of 90 days” from “the date the alien is
released from [state or local] detention or confinement”;
however, it “may not remove an alien who is sentenced to
imprisonment until the alien is released from
imprisonment.” Id. § 1231(a)(1), (4) (emphasis added).
After release, federal authorities “shall detain the alien,” and
“[u]nder no circumstance during the removal period shall the
Attorney General release an alien who has been found
inadmissible . . . or deportable.” Id. § 1231(a)(2).

    The United States asserts that “Congress contemplated
cooperation between federal and state officials” when it
allowed noncitizens to complete state criminal custody
before removal, and points to “other provisions of the INA
          UNITED STATES V. STATE OF CALIFORNIA               13

[that] likewise reflect that expectation of collaboration.” For
example, the federal government is required to make
information available to state and local authorities indicating
“whether individuals arrested . . . for aggravated felonies are
aliens,” and to provide liaisons and computer resources in
connection with aliens charged with aggravated felonies. Id.
§ 1226(d)(1). Additionally, DHS must respond to inquiries
from state or local officials “seeking to verify or ascertain
the citizenship or immigration status of any individual.” Id.
§ 1373(c). In turn, “a Federal, State, or local government
entity or official may not prohibit, or in any way restrict, any
government entity or official from sending to, or receiving
from, [DHS] information regarding the citizenship or
immigration status, lawful or unlawful, of any individual.”
Id. § 1373(a). Additionally, “[f]ederal law specifies limited
circumstances in which state officers may perform the
functions of an immigration officer,” such as “when the
Attorney General has granted that authority to specific
officers in a formal agreement with a state or local
government.” Arizona II, 567 U.S. at 408 (citing 8 U.S.C.
§§ 1103(a)(10), 1252c, 1324(c), 1357(g)(1)).             “State
officials can also assist the Federal Government by
responding to requests for information about when an alien
will be released from their custody.” Id. at 410.

       ii. The IRCA

    Congress enacted the Immigration Reform and Control
Act of 1986 (IRCA) “as a comprehensive framework for
‘combating the employment of illegal aliens.’” Arizona II,
567 U.S. at 404 (quoting Hoffman Plastic Compounds, Inc.
v. NLRB, 535 U.S. 137, 147 (2002)). Under the IRCA,
employers may not knowingly hire or employ aliens without
proper work authorization. 8 U.S.C. § 1324a(a)(1)–(2).
Employers in violation of the IRCA are subject to civil and,
14        UNITED STATES V. STATE OF CALIFORNIA

in cases of “a pattern or practice of violations,” criminal
penalties. Id. § 1324a(e)–(f). Although the IRCA

        does not impose federal criminal sanctions on
        the employee side . . . . some civil penalties
        are imposed instead.            With certain
        exceptions, aliens who accept unlawful
        employment are not eligible to have their
        status adjusted to that of a lawful permanent
        resident. Aliens also may be removed from
        the country for having engaged in
        unauthorized work. In addition to specifying
        these civil consequences, federal law makes
        it a crime for unauthorized workers to obtain
        employment through fraudulent means.

Arizona II, 567 U.S. at 404–05 (citations omitted).

    To ensure compliance with the IRCA, employers must
verify the authorization statuses of prospective employees.
8 U.S.C. § 1324a(a)(1)(B), (b). Verification is facilitated
through a uniform inspection process; employers are
required to retain documentary evidence of authorized
employment, to which “immigration officers and
administrative law judges [] have reasonable access.” Id.
§ 1324a(b), (e)(2)(A). The information and documentation
associated with the verification process may only be used to
enforce the IRCA and INA, as well as for prosecution under
certain criminal statutes. Id. § 1324a(b)(5), (d)(2)(F)–(G).

     B. California’s Statutes

    This case centers on three laws enacted by the California
legislature with the express goal “of protecting immigrants
from an expected increase in federal immigration
enforcement actions.” Hearing on AB 450 Before the
          UNITED STATES V. STATE OF CALIFORNIA                    15

Assemb. Comm. on Judiciary, 2017–18 Sess. 1 (Cal. 2017)
(synopsis).

        i. Immigrant Worker Protection Act (AB 450)

    AB 450 prohibits “public and private employers” from
“provid[ing] voluntary consent to an immigration
enforcement agent to enter any nonpublic areas of a place of
labor,” unless “the immigration enforcement agent provides
a judicial warrant.” Cal. Gov’t Code § 7285.1(a), (e). It
similarly prohibits employers from “provid[ing] voluntary
consent to an immigration enforcement agent to access,
review, or obtain the employer’s employee records without
a subpoena or judicial warrant.” Id. § 7285.2(a)(1). It also
limits employers’ ability to “reverify the employment
eligibility of a current employee at a time or in a manner not
required by” the IRCA. Cal. Lab. Code § 1019.2(a).

    In addition, AB 450 requires employers to “provide a
notice to each current employee, by posting in the language
the employer normally uses to communicate employment-
related information to the employee, of any inspections of
I-9 Employment Eligibility Verification forms or other
employment records conducted by an immigration agency
within 72 hours of receiving notice of the inspection.” Id.
§ 90.2(a)(1). 1    If an employer receives “the written
immigration agency notice that provides the results of the
inspection,” then she must provide a copy to each “employee
identified by the immigration agency inspection results to be
an employee who may lack work authorization” and each

    1
      AB 450 “does not require a penalty to be imposed upon an
employer or person who fails to provide notice to an employee at the
express and specific direction or request of the federal government.”
Cal. Lab. Code § 90.2(c).
16         UNITED STATES V. STATE OF CALIFORNIA

“employee whose work authorization documents have been
identified by the immigration agency inspection to have
deficiencies.” Id. § 90.2(b)(1)–(2).

         ii. Inspection and Review of Facilities Housing
             Federal Detainees (AB 103)

     AB 103 requires the California Attorney General to
conduct “reviews of county, local, or private locked
detention facilities in which noncitizens are being housed or
detained for purposes of civil immigration proceedings in
California.” Cal. Gov’t Code § 12532(a). 2 This includes
“any county, local, or private locked detention facility in
which an accompanied or unaccompanied minor is housed
or detained on behalf of, or pursuant to a contract with, the
federal Office of Refugee Resettlement or the United States
Immigration and Customs Enforcement.” Id. It requires the
California Attorney General to review “the conditions of
confinement,” “the standard of care and due process
provided,” and “the circumstances around [the]
apprehension” of civil immigration detainees, and then
prepare “a comprehensive report outlining the findings of the
review.” Id. § 12532(b). To facilitate this review, the
California Attorney General “shall be provided all necessary
access for the observations necessary to effectuate reviews
required pursuant to this section, including, but not limited
to, access to detainees, officials, personnel, and records.” Id.
§ 12532(c).

         iii. California Values Act (SB 54)


     2
       California law generally requires biennial inspections of “local
detention facilities,” focusing on health and safety, fire suppression,
security, and rehabilitation efforts. Cal. Penal Code § 6031.1(a).
            UNITED STATES V. STATE OF CALIFORNIA                         17

     SB 54 limits law enforcement’s “discretion to cooperate
with immigration authorities.” Id. § 7282.5(a). Among
other things, it prohibits state and local law enforcement
agencies from “[i]nquiring into an individual’s immigration
status”; “[d]etaining an individual on the basis of a hold
request”; “[p]roviding information regarding a person’s
release date or” other “personal information,” such as “the
individual’s home address or work address”; and “[a]ssisting
immigration authorities” in certain activities.            Id.
§ 7284.6(a)(1). SB 54 contains some exceptions to these
prohibitions. For example, although agencies generally
cannot “[t]ransfer an individual to immigration authorities,”
such an undertaking is permissible if “authorized by a
judicial warrant or judicial probable cause determination,”
or if the individual has been convicted of certain enumerated
crimes. Id. §§ 7282.5(a), 7284.6(a)(4). Similarly, the
restrictions on sharing personal information are also relaxed
if the individual has been convicted of an enumerated crime,
or if the information is available to the public. Id.
§§ 7282.5(a), 7284.6(a)(1)(C)–(D). 3


    3
       California asserts that SB 54 was motivated by its “recogni[tion]
that victims and witnesses of crime are less likely to come forward if
they fear that an interaction with law enforcement will lead to their
removal or the removal of a family member,” and that the law built upon
prior legislative efforts. See Cal. Penal Code § 422.93 (“Whenever an
individual who is a victim of or witness to a hate crime . . . is not charged
with or convicted of committing any crime under state law, a peace
officer may not detain the individual exclusively for any actual or
suspected immigration violation or report or turn the individual over to
federal immigration authorities.”); see also Cal. Gov’t Code § 7284.2
(outlining the legislative findings undergirding SB 54 and reporting that
“immigrant community members fear approaching police” and
“[e]ntangling state and local agencies with federal immigration
enforcement programs diverts already limited resources and blurs the
lines of accountability between local, state, and federal governments”).
18         UNITED STATES V. STATE OF CALIFORNIA

II. Procedural Background

    On March 6, 2018, the United States filed this action
against California, alleging that AB 450, AB 103, and SB 54
are preempted and violate the Supremacy Clause. The
United States moved to preliminarily enjoin the three laws.

     The district court granted the motion for a preliminary
injunction in part and denied it in part. United States v.
California (California I), 314 F. Supp. 3d 1077, 1112 (E.D.
Cal. 2018). It agreed that the United States was likely to
succeed on the merits as to two provisions of AB 450—
specifically, the restriction on employers’ voluntary consent
to immigration enforcement officers, which the court
concluded “impermissibly discriminates against those who
choose to deal with the Federal Government,” and AB 450’s
reverification provision, which it determined was likely
preempted. Id. at 1096, 1098. 4 However, the court found
“no merit to [the United States’] Supremacy Clause claim as
to” AB 450’s employee-notice provisions, reasoning,
“Given IRCA’s focus on employers, the Court finds no
indication—express or implied—that Congress intended for
employees to be kept in the dark.” Id. at 1097. The notice
provisions did not “violate the intergovernmental immunity
doctrine,” the district court continued, because “[a]n
employer is not punished for its choice to work with the
Federal Government, but for its failure to communicate with
its employees.” Id.

    As to AB 103, the district court found “no indication in
the cited portions of the INA that Congress intended for


    4
      California does not appeal the partial grant of the United States’
motion.
         UNITED STATES V. STATE OF CALIFORNIA               19

States to have no oversight over detention facilities operating
within their borders,” noting that

       AB 103’s review process does not purport to
       give California a role in determining whether
       an immigrant should be detained or removed
       from the country. The directive contemplates
       increased transparency and a report that may
       serve as a baseline for future state or local
       action. At this point, what that future action
       might be is subject to speculation and
       conjecture.

Id. at 1091. It further concluded that AB 103 was not invalid
under the doctrine of intergovernmental immunity because
“the burden placed upon the facilities is minimal,” and “even
if AB 103 treats federal contractors differently than the State
treats other detention facilities,” the United States had not
demonstrated that California “treats other facilities better
than those contractors.” Id. at 1093.

    The district court also refused to enjoin the challenged
provisions of SB 54, finding that California’s “decision not
to assist federal immigration enforcement in its endeavors is
not an ‘obstacle’ to that enforcement effort” because
“refusing to help is not the same as impeding,” and thus the
doctrine of obstacle preemption did not render the provisions
unlawful. Id. at 1104–05. It also found that “Tenth
Amendment and anticommandeering principles counsel
against preemption,” and that 8 U.S.C. § 1373, which
governs the exchange of “information regarding []
immigration status,” did not change this conclusion because
the “plain meaning of Section 1373 limits its reach to
information strictly pertaining to immigration status (i.e.
what one’s immigration status is) and does not include
20       UNITED STATES V. STATE OF CALIFORNIA

information like release dates and addresses.” Id. at 1102,
1107. The district court determined that “a Congressional
mandate prohibiting states from restricting their law
enforcement agencies’ involvement in immigration
enforcement activities—apart from, perhaps, a narrowly
drawn information sharing provision—would likely violate
the Tenth Amendment.” Id. at 1109–10.

    Subsequently, the district court ruled on California’s
motion to dismiss, issuing an order consistent with its
conclusions as to the preliminary injunction. United States
v. California (California II), No. 2:18-cv-490-JAM-KJN,
2018 WL 3361055, at *1 (E.D. Cal. July 9, 2018). This
timely appeal followed.

     STANDARD OF REVIEW AND JURISDICTION

     We review a district court’s denial of a preliminary
injunction for abuse of discretion. Epona v. County of
Ventura, 876 F.3d 1214, 1219 (9th Cir. 2017). “Our review
is limited and deferential. The district court’s interpretation
of the underlying legal principles, however, is subject to de
novo review and a district court abuses its discretion when it
makes an error of law.” Sw. Voter Registration Educ.
Project v. Shelley, 344 F.3d 914, 918 (9th Cir. 2003) (en
banc) (per curiam). We will therefore reverse a denial of a
preliminary injunction if the district court “based [its
decision] on an erroneous legal standard or a clearly
erroneous finding of fact.” Associated Press v. Otter,
682 F.3d 821, 824 (9th Cir. 2012) (quoting Pimentel v.
Dreyfus, 670 F.3d 1096, 1105 (9th Cir. 2012)).
           UNITED STATES V. STATE OF CALIFORNIA                         21

    We have jurisdiction over the United States’ appeal of
the denial of its motion for a preliminary injunction pursuant
to 28 U.S.C. § 1292. 5

                             ANALYSIS

    “A plaintiff seeking a preliminary injunction must
establish that he is likely to succeed on the merits, that he is
likely to suffer irreparable harm in the absence of
preliminary relief, that the balance of equities tips in his
favor, and that an injunction is in the public interest.” Winter

     5
       The United States’ notice of appeal is directed to both the district
court’s preliminary injunction order and its order granting in part and
denying in part California’s motion to dismiss. Although we have
appellate jurisdiction over appeal of the preliminary injunction order
pursuant to 28 U.S.C. § 1292(a)(1) (conferring jurisdiction over
“[i]nterlocutory orders of the district courts . . . granting, continuing,
modifying, refusing or dissolving injunctions”), we do not have
jurisdiction over an appeal of the dismissal order. Since the district court
did not grant California’s motion to dismiss in its entirety, that order was
not a “full adjudication of the issues” and did not “clearly evidence[] the
judge’s intention that it be the court’s final act in the matter,” Nat’l
Distrib. Agency v. Nationwide Mut. Ins. Co., 117 F.3d 432, 433 (9th Cir.
1997) (quoting In re Slimick, 928 F.2d 304, 307 (9th Cir. 1990)), and
therefore was not final pursuant to 28 U.S.C. § 1291. See Prellwitz v.
Sisto, 657 F.3d 1035, 1038 (9th Cir. 2011) (“[T]he district court’s order
was not final because it did not dispose of the action as to all claims
between the parties.”). Indeed, it is quite clear that the order was not the
court’s final act in the matter, since it subsequently granted the United
States’ motion to stay further proceedings pending the outcome of this
appeal. See United States v. California, No. 2:18-cv-00490-JAM-KJN,
2018 WL 5310675, at *1 (E.D. Cal. Oct. 19, 2018).

     The district court did not certify the non-final dismissal order
pursuant to Federal Rule of Civil Procedure 54(b) or 28 U.S.C.
§ 1292(b), and no other apparent exceptions to the finality rule exist here.
We therefore DISMISS the appeal of the district court’s dismissal order
for want of appellate jurisdiction.
22       UNITED STATES V. STATE OF CALIFORNIA

v. Nat. Res. Def. Council, Inc., 555 U.S. 7, 20 (2008). Here,
as the United States observes, the district court’s “sole basis
for denying injunctive relief against the California laws at
issue in this appeal was the court’s assessment of the merits,”
which, it further argues, “was erroneous because the district
court adopted an unduly narrow view of two related
doctrines, intergovernmental immunity and conflict
preemption.”

    The doctrine of intergovernmental immunity is derived
from the Supremacy Clause, U.S. Const., art. VI, which
mandates that “the activities of the Federal Government are
free from regulation by any state.” Boeing Co. v.
Movassaghi, 768 F.3d 832, 839 (9th Cir. 2014) (quoting
Mayo v. United States, 319 U.S. 441, 445 (1943)).
“Accordingly, state laws are invalid if they ‘regulate[] the
United States directly or discriminate[] against the Federal
Government or those with whom it deals.’” Id. (alterations
in original) (quoting North Dakota v. United States, 495 U.S.
423, 435 (1990) (plurality opinion)).

    Under the doctrine of conflict preemption, “state laws
are preempted when they conflict with federal law. This
includes cases where ‘compliance with both federal and state
regulations is a physical impossibility,’ and those instances
where the challenged state law ‘stands as an obstacle to the
accomplishment and execution of the full purposes and
objectives of Congress.’” Arizona II, 567 U.S. at 399
(citations omitted) (first quoting Fla. Lime & Avocado
Growers, Inc. v. Paul, 373 U.S. 132, 142–43 (1963); and
then quoting Hines v. Davidowitz, 312 U.S. 52, 67 (1941)).
The latter instances constitute so-called “obstacle
preemption,” and “[t]o determine whether obstacle
preemption exists, the Supreme Court has instructed that we
employ our ‘judgment, to be informed by examining the
         UNITED STATES V. STATE OF CALIFORNIA               23

federal statute as a whole and identifying its purpose and
intended effects.’” United States v. Arizona (Arizona I),
641 F.3d 339, 345 (9th Cir. 2011) (quoting Crosby v. Nat’l
Foreign Trade Council, 530 U.S. 363, 373 (2000)), aff’d in
part, rev’d in part, 567 U.S. 387 (2012). The Court has
emphasized that “[i]mplied preemption analysis does not
justify a ‘freewheeling judicial inquiry into whether a state
statute is in tension with federal objectives’; such an
endeavor ‘would undercut the principle that it is Congress
rather than the courts that preempts state law.’ . . . [A] high
threshold must be met if a state law is to be preempted for
conflicting with the purposes of a federal Act.” Chamber of
Commerce of U.S. v. Whiting, 563 U.S. 582, 607 (2011)
(quoting Gade v. Nat’l Solid Wastes Mgmt. Ass’n, 505 U.S.
88, 110–11 (1992) (Kennedy, J., concurring in part and
concurring in the judgment)).

    “Under these principles,” the United States contends,
“the challenged provisions of California law are invalid and
should have been enjoined.” We consider each statute in
turn.

I. AB 450

    AB 450, which imposes penalties on employers based on
their interactions with federal immigration authorities, was
partially enjoined by the district court; specifically, its
provisions relating to employers who provide consent to
federal investigations or reverify the employment eligibility
of current employees. The district court did not, however,
enjoin the provisions of AB 450 that establish employee-
notice requirements. The United States maintains that “these
provisions violate the intergovernmental immunity doctrine
and are also subject to obstacle preemption.”
24       UNITED STATES V. STATE OF CALIFORNIA

    Congress enacted the IRCA to combat the employment
of unauthorized noncitizens. Arizona II, 567 U.S. at 404–
05. Employers are required to retain documentation
regarding employees’ work authorizations, and to make that
documentation available for inspection by federal officers.
8 U.S.C. § 1324a(b)(3). Such inspections must be preceded
by “at least three business days notice.” 8 C.F.R.
§ 274a.2(b)(2)(ii). The United States notes that “[n]either
the statute nor the regulations require any notice to
employees before their employers’ records are inspected, or
after an inspection is conducted.” AB 450, by contrast,
requires two forms of notice: first, employers must inform
their employees of upcoming inspections within 72 hours of
receiving notice, Cal. Lab. Code § 90.2(a)(1), and second,
employers must share any documents providing the results
of the inspection with any employees who might lack work
authorization, id. § 90.2(b)(1)–(2).

     A. Intergovernmental Immunity

     The United States contends that “AB 450’s provisions
impermissibly target and discriminate against federal
immigration enforcement operations.” It reasons that “[i]f
any other entity—such as a state or federal regulator, or a
private entity—inspects an employer’s records, the
employer would have no obligation under AB 450 to notify
its employees,” and thus that AB 450 impermissibly imposes
a “unique regime” on the federal government.

   This argument, however, extends intergovernmental
immunity beyond its defined scope. The doctrine has been
invoked, to give a few examples, to prevent a state from
imposing more onerous clean-up standards on a federal
hazardous waste site than a non-federal project, Boeing,
768 F.3d at 842–43; to preclude cities from banning only the
U.S. military and its agents from recruiting minors, United
         UNITED STATES V. STATE OF CALIFORNIA               25

States v. City of Arcata, 629 F.3d 986, 988, 990–92 (9th Cir.
2010); and to foreclose a state from taxing the lessees of
federal property while exempting from the tax lessees of
state property, Phillips Chem. Co. v. Dumas Indep. Sch.
Dist., 361 U.S. 376, 381–82, 387 (1960). Those cases dealt
with laws that directly or indirectly affected the operation of
a federal program or contract. The situation here is
distinguishable—AB 450 is directed at the conduct of
employers, not the United States or its agents, and no federal
activity is regulated. We agree with California: “The mere
fact that those notices contain information about federal
inspections does not convert them into a burden on those
inspections.” Similarly, the mere fact that the actions of the
federal government are incidentally targeted by AB 450
does not mean that they are incidentally burdened, and while
the latter scenario might implicate intergovernmental
immunity, the former does not. As the district court
correctly recognized, to rule otherwise “would stretch the
doctrine beyond its borders.” California I, 314 F. Supp. 3d
at 1097.

    The United States argues that the proposition that
intergovernmental immunity is only implicated when federal
activities are obstructed “is clearly wrong, because it would
render the intergovernmental-immunity doctrine entirely
redundant with the obstacle-preemption doctrine, which
separately addresses the burdensome effect of non-
discriminatory state laws.” We disagree. The United States
does not accurately distinguish between the doctrines of
intergovernmental immunity and obstacle preemption.
Reviewing the case law in which these doctrines were
developed yields the proper distinction: simply put,
intergovernmental immunity attaches only to state laws that
discriminate against the federal government and burden it in
some way. Obstacle preemption, by contrast, attaches to any
26       UNITED STATES V. STATE OF CALIFORNIA

state law, regardless of whether it specifically targets the
federal government, but only if it imposes an obstructive,
not-insignificant burden on federal activities.

     Moreover, the United States’ position that no obstruction
is required in intergovernmental immunity cases ignores the
origins of the doctrine and the occasions in which it has been
applied. “The doctrine of intergovernmental immunity arose
from the Supreme Court’s decision in M’Culloch v.
Maryland, which established that ‘the states have no power,
by taxation or otherwise, to retard, impede, burden, or in any
manner control, the operations of the constitutional laws
enacted by congress to carry into execution the powers
vested in the general government.’” City of Arcata, 629 F.3d
at 991 (emphasis added) (citation omitted) (quoting
M’Culloch v. Maryland, 17 U.S. (4 Wheat.) 316, 436
(1819)); see also North Dakota, 495 U.S. at 437–38
(plurality opinion) (“The nondiscrimination rule finds its
reason in the principle that the States may not directly
obstruct the activities of the Federal Government.”
(emphasis added)); Washington v. United States, 460 U.S.
536, 544 (1983) (“The important consideration . . . is not
whether the State differentiates in determining what entity
shall bear the legal incidence of the tax, but whether the tax
is discriminatory with regard to the economic burdens that
result.” (emphasis added)); City of Arcata, 629 F.3d at 991
(applying the nondiscrimination rule to ordinances that
“specifically target and restrict the conduct of military
recruiters” (emphasis added)).

    Since the advent of the doctrine, intergovernmental
immunity has attached where a state’s discrimination
negatively affected federal activities in some way. It is not
implicated when a state merely references or even singles
out federal activities in an otherwise innocuous enactment.
           UNITED STATES V. STATE OF CALIFORNIA                    27

The Supreme Court has clarified that a state “does not
discriminate against the Federal Government and those with
whom it deals unless it treats someone else better than it
treats them.” Washington, 460 U.S. at 544–45. AB 450 does
not treat the federal government worse than anyone else;
indeed, it does not regulate federal operations at all.
Accordingly, the district court correctly concluded that
AB 450’s employee-notice provisions do not violate the
doctrine of intergovernmental immunity.

    B. Preemption

    The United States also contends that AB 450’s
employee-notice provisions are preempted because they
seek “to alter the manner in which the federal government
conducts inspections, by imposing requirements that neither
Congress nor the implementing agency saw fit to impose.”
We disagree. The cases to which the United States cites
concerned either the disruption of a federal relationship or
the undermining of a federal operation. Here, there is
indisputably a federal relationship, but it is between federal
immigration authorities and the employers they regulate 6—
not between employers and their employees. AB 450
impacts the latter relationship, not the former, and imposes
no additional or contrary obligations that undermine or
disrupt the activities of federal immigration authorities. In
Arizona II, the Supreme Court observed that a “[c]onflict in
technique can be fully as disruptive to the system Congress
erected as conflict in overt policy.” 567 U.S. at 406

    6
      Cf. Buckman Co. v. Plaintiffs’ Legal Comm., 531 U.S. 341, 347
(2001) (“[T]he relationship between a federal agency and the entity it
regulates is inherently federal in character because the relationship
originates from, is governed by, and terminates according to federal
law.”).
28       UNITED STATES V. STATE OF CALIFORNIA

(alteration in original) (quoting Amalgamated Ass’n of St.,
Elec. Ry. & Motor Coach Emps. of Am. v. Lockridge,
403 U.S. 274, 287 (1971)); see also Crosby, 530 U.S. at
376–77 (finding preempted a state law “imposing a different,
state system” that “undermines the President’s intended
statutory authority”). Here, by contrast, there is no “conflict
in technique,” because federal activity is not regulated.

    AB 450’s employee-notice provisions do not permit
employers to hire individuals without federally defined
authorization, or impose sanctions inconsistent with federal
law, either of which would impermissibly “frustrate[] the
purpose of the national legislation or impair[] the efficiency
of those agencies of the Federal government.” Nash v. Fla.
Indus. Comm’n, 389 U.S. 235, 240 (1967) (quoting Davis v.
Elmira Sav. Bank, 161 U.S. 275, 283 (1896)). But “nothing
in IRCA (or federal immigration policy generally) demands
that employers, site owners, or general contractors be
absolved from” a state’s employee-protection efforts
“whenever undocumented aliens provide labor.” Madeira v.
Affordable Hous. Found., Inc., 469 F.3d 219, 242 (2d Cir.
2006); see also id. at 241–42 (finding no preemption where
“[t]here is no irreconcilable conflict between IRCA and [a
state workplace-protection law] such that compliance with
both the former’s prohibition on the employment of
undocumented workers and the latter’s safe construction site
obligation is physically impossible”). In the absence of
irreconcilability, there is no conflict preemption, as the
district court correctly recognized. See California I, 314 F.
Supp. 3d at 1097.

II. AB 103

    AB 103 authorizes the California Attorney General to
inspect detention facilities that house civil immigration
detainees. The United States contends that the law
           UNITED STATES V. STATE OF CALIFORNIA                        29

“impermissibly seeks to require facilities housing federal
immigration detainees to cooperate with broad
investigations that examine the due process provided to
detainees and the circumstances surrounding the detainee’s
apprehension and transfer to the facility.” Again, it invokes
intergovernmental immunity and obstacle preemption.

    A. Intergovernmental Immunity

    Like AB 450, AB 103 relates exclusively to federal
conduct, as it applies only to “facilities in which noncitizens
are being housed or detained for purposes of civil
immigration proceedings in California.” Cal. Gov’t Code
§ 12532(a). 7 Unlike AB 450, AB 103 imposes a specialized
burden on federal activity, as the district court recognized.
See California I, 314 F. Supp. 3d at 1093. That vital



    7
      To “arrange for appropriate places of detention for aliens detained
pending removal or a decision on removal,” 8 U.S.C. § 1231(g)(1), the
INA contemplates use of both federal facilities and nonfederal facilities
with which the federal government contracts. See id. § 1231(g)(2)
(requiring the federal government to “consider the availability for
purchase or lease of any existing prison, jail, detention center, or other
comparable facility suitable for” detainee detention); id. § 1103(a)(11)
(authorizing “payments” to and “cooperative agreement[s]” with states
and localities). For purposes of intergovernmental immunity, federal
contractors are treated the same as the federal government itself. See
Goodyear Atomic Corp. v. Miller, 486 U.S. 174, 181 (1988) (“[A]
federally owned facility performing a federal function is shielded from
direct state regulation, even though the federal function is carried out by
a private contractor, unless Congress clearly authorizes such
regulation.”); Gartrell Constr. Inc. v. Aubry, 940 F.2d 437, 438–41 (9th
Cir. 1991) (holding that state licensing requirements for construction
contractors were preempted to the extent that they applied to federal
contractors).
30         UNITED STATES V. STATE OF CALIFORNIA

distinction renders the burdensome provisions of AB 103
unlawful under the doctrine of intergovernmental immunity.

    Prior to the enactment of AB 103, California law already
required periodic inspections of prisons and detainment
facilities. See Cal. Penal Code § 6031.1 (mandating biennial
inspections of “[h]ealth and safety,” “[f]ire suppression
preplanning,”      “[s]ecurity,   rehabilitation   programs,
recreation, treatment of persons confined in the facilities,
and personnel training,” and visitation conditions, as well as
the completion of subsequent reports). AB 103, however,
does not merely replicate this inspection scheme; in addition
to requiring “[a] review of the conditions of confinement,”
the enactment also calls for reviews of the “standard of care
and due process provided to” detainees, and “the
circumstances around their apprehension and transfer to the
facility.” Cal. Gov’t Code § 12532(b)(1). These additional
requirements burden federal operations, and only federal
operations. 8



     8
        The statute requires that the California Attorney General “be
provided all necessary access for the observations necessary to effectuate
reviews required pursuant to this section, including, but not limited to,
access to detainees, officials, personnel, and records.” Cal. Gov’t Code
§ 12532(c). Immigration and Customs Enforcement (ICE) official
Thomas Homan claimed that “[t]hese inspections have caused the
facilities to expend resources otherwise necessary for ensuring the safety
and security of the detainees. Each inspection presents a burdensome
intrusion into facility operations and pulls scarce resources away from
other sensitive law enforcement tasks.” Homan also attested that “the
broad allowances made by AB 103 for the California [Attorney General]
to perform reviews of immigration detention facilities to include wide-
ranging access to facilities, individuals, and records, if enforced by the
state, will conflict with ICE’s ability to comply with other federal
information disclosure laws, regulations, and policies.”
         UNITED STATES V. STATE OF CALIFORNIA              31

    The district court addressed this burden as follows: “[The
United States] argues the law violates [the doctrine of
intergovernmental immunity] because it imposes a review
scheme on facilities contracting with the federal
government, only. This characterization is valid. However,
the burden placed upon the facilities is minimal and [the
United States’] evidence does not show otherwise.”
California I, 314 F. Supp. 3d at 1093. Instead of challenging
the factual conclusion regarding the severity of AB 103’s
burden, the United States questions the district court’s legal
conclusion, contending that “the application of the
intergovernmental immunity doctrine does not depend on
the size of the discriminatory burden imposed. Even a tax of
$1 imposed only on entities that contract with the federal
government would be unlawful.” In essence, the district
court applied a de minimis exception to the doctrine of
intergovernmental       immunity,      concluding     that   a
discriminatory enactment is lawful so long as the burden it
imposes on the federal government is minimal. But the court
cited no authority for this proposition. We must therefore
determine whether such an exception is cognizable.

       i. De Minimis Exception

   We agree with the United States that Supreme Court case
law compels the rejection of a de minimis exception to the
doctrine of intergovernmental immunity.

    The recent decision in Dawson v. Steager, 139 S. Ct. 698
(2019), supports this position. There, the Court suggested
that any discriminatory burden on the federal government is
impermissible, writing that “[s]ection 111 disallows any
state tax that discriminates against a federal officer or
employee.” Id. at 704 (citing 4 U.S.C. § 111). The Court
had previously explained that the prohibition against
discriminatory taxes in § 111 “is coextensive with the
32         UNITED STATES V. STATE OF CALIFORNIA

prohibition against discriminatory taxes embodied in the
modern constitutional doctrine of intergovernmental tax
immunity.” Davis v. Mich. Dep’t of Treasury, 489 U.S. 803,
813 (1989).

    The parties do not dispute that the principles of the
intergovernmental tax immunity doctrine apply to the
general intergovernmental immunity doctrine. See North
Dakota, 495 U.S. at 434–39 (plurality opinion).
Accordingly, we are not prepared to recognize a de minimis
exception to the doctrine of intergovernmental immunity.
Any economic burden that is discriminatorily imposed on the
federal government is unlawful. 9 In relying on a de minimis
exception, the district court applied incorrect law and
therefore abused its discretion.

         ii. Burdensome Provisions

    That is not to say, however, that the United States is
likely to succeed on the merits as to the entirety of AB 103.
Only those provisions that impose an additional economic


     9
      We note the practical merit of this conclusion. Rejecting a de
minimis exception permits a clearer distinction between
intergovernmental immunity and the related—but distinct—doctrine of
obstacle preemption. Intergovernmental immunity is implicated when
any burden is imposed exclusively on the federal government; obstacle
preemption is implicated when an obstructive burden is imposed,
regardless of its discriminatory nature. Our conclusion is also consistent
with M’Culloch, the seminal intergovernmental immunity decision.
There, the Supreme Court was loath to undertake the “perplexing
inquiry, so unfit for the judicial department, what degree of taxation is
the legitimate use, and what degree may amount to the abuse of the
power,” and opined that “[a] question of constitutional power can hardly
be made to depend on a question of more or less.” M’Culloch, 17 U.S.
(4 Wheat.) at 327, 430.
         UNITED STATES V. STATE OF CALIFORNIA            33

burden exclusively on the federal government are invalid
under the doctrine of intergovernmental immunity.

    California maintains that all of AB 103’s requirements
duplicate preexisting inspection demands imposed on state
and local detention facilities. It points to regulations
requiring its Board of State and Community Corrections (the
Board) to inspect not only compliance with general health
and safety standards—which are included in AB 103, see
Cal. Gov’t Code § 12532(b)(1)(A)–(B) (requiring review of
“the conditions of confinement” and “the standard of care”
of detainees)—but also the availability of legal reference
materials and confidential communications with counsel.
See Cal. Penal Code § 6031.1; Cal. Code Regs. tit. 15,
§§ 1063–64, 1068. California argues that AB 103’s
requirement that the California Attorney General review the
“due process provided to” civil immigration detainees, Cal.
Gov’t Code § 12532(b)(1)(B), is therefore duplicative, on
the assumption that “due process” refers to “conditions of
confinement that affect detainees’ ability to access courts—
such as the adequacy of the facility’s law library, the
availability of unmonitored communications with counsel,
and the ability to send and receive mail.” See Bounds v.
Smith, 430 U.S. 817, 828 (1977) (recognizing that “the
fundamental constitutional right of access to the courts
requires prison authorities to assist inmates in the
preparation and filing of meaningful legal papers by
providing prisoners with adequate law libraries or adequate
assistance from persons trained in the law”); Cornett v.
Donovan, 51 F.3d 894, 897–98 (9th Cir. 1995) (finding that
the Bounds right is “not limited to people who are committed
following criminal proceedings”). At oral argument,
California maintained that its Attorney General’s
interpretation of “due process” is indeed as limited as its
brief suggests, and thus does not compel any additional
34        UNITED STATES V. STATE OF CALIFORNIA

inspection requirements beyond those applied to other state
facilities.

    In the context of this appeal from the denial of a
preliminary injunction, we accept California’s limited
construction. We therefore conclude that AB 103’s due
process provision likely does not violate the doctrine of
intergovernmental immunity, and that the district court’s
denial of a preliminary injunction as to this provision should
be affirmed. We note, however, that a broader reading of the
term “due process” might empower the California Attorney
General to scrutinize, say, an immigration judge’s analysis,
the results of the Board of Immigration Appeals, or other
related court proceedings—all of which are well outside the
purview of a state attorney general, and not duplicative of
the inspection requirements otherwise imposed on
California’s state and local detention facilities.

    That is not the end of our inquiry, for as the United States
observes, California “does not even attempt to identify any
provision of the pre-existing inspection scheme analogous to
the unique requirement for immigration detainees that
inspectors must examine the circumstances surrounding
their apprehension and transfer to the facility.” See Cal.
Gov’t Code § 12532(b)(1)(C). This is a novel requirement,
apparently distinct from any other inspection requirements
imposed by California law. The district court was therefore
incorrect when it concluded that “the review appears no
more burdensome than reviews required under California
Penal Code §§ 6030, 6031.1.” California I, 314 F. Supp. 3d
at 1093.

    In light of this apparent factual error, and the district
court’s erroneous reliance on a de minimis exception to the
doctrine of intergovernmental immunity, we reverse the
district court’s denial of a preliminary injunction as to
         UNITED STATES V. STATE OF CALIFORNIA              35

California Government Code section 12532(b)(1)(C)—the
provision of AB 103 requiring examination of the
circumstances surrounding the apprehension and transfer of
immigration detainees.

   B. Preemption

    The United States further argues that “even if AB 103’s
inspection regime had not discriminatorily targeted facilities
holding federal immigration detainees, it still would be
preempted by federal law.” We disagree.

    The cases on which the United States relies involved a
far clearer interference with federal activity than AB 103
creates. In Leslie Miller, Inc. v. Arkansas, 352 U.S. 187,
189–90 (1956) (per curiam), and Gartrell Construction Inc.
v. Aubry, 940 F.2d 437, 441 (9th Cir. 1991), states prevented
the federal government from entering into agreements with
its chosen contractors until the states’ own licensing
standards were satisfied. In Tarble’s Case, the Supreme
Court rejected a state court’s attempt to discharge a prisoner
held “by an officer of the United States, under claim and
color of the authority of the United States, as an enlisted
soldier mustered into the military service of the National
government.” 80 U.S. (13 Wall.) 397, 412 (1871). In In re
Neagle, the Court determined that a county sheriff could not
hold a U.S. marshal on murder charges for actions taken on
duty. 135 U.S. 1, 62 (1890).

    These cases evinced states’ active frustration of the
federal government’s ability to discharge its operations.
Here, by contrast, AB 103 does not regulate whether or
where an immigration detainee may be confined, require that
federal detention decisions or removal proceedings conform
to state law, or mandate that ICE contractors obtain a state
license. The law might require some federal action to permit
36         UNITED STATES V. STATE OF CALIFORNIA

inspections and produce data—a burden that, as discussed
above, implicates intergovernmental immunity—but as
California persuasively notes, “[M]ere collection of such
factual data does not (and cannot) disturb any federal arrest
or detention decision.”

    In Arizona II, the Supreme Court noted that “[i]n
preemption analysis, courts should assume that ‘the historic
police powers of the States’ are not superseded ‘unless that
was the clear and manifest purpose of Congress.’” 567 U.S.
at 400 (quoting Rice v. Santa Fe Elevator Corp., 331 U.S.
218, 230 (1947)). The United States does not dispute that
California possesses the general authority to ensure the
health and welfare of inmates and detainees in facilities
within its borders, and neither the provisions of the INA that
permit the federal government to contract with states and
localities for detention purposes, see 8 U.S.C.
§§ 1103(a)(11), 1231(g), nor the contracts themselves, 10

     10
         The contracts included in the record require that immigration
facilities conform to California’s authority. One contract—between
DHS and the City of Holtville, California, for use of the Imperial
Regional Detention Facility—includes a provision requiring
“compl[iance] with all applicable ICE, federal, state and local laws,
statutes, regulations, and codes. In the event there is more than one
reference to a safety, health, or environment requirement . . . the most
stringent requirement shall apply.” Another agreement between the
Office of the Federal Detention Trustee and a private contractor,
Corrections Corporation of America, to house ICE detainees in San
Diego County similarly required that “[a]ll services and programs shall
comply with . . . all applicable federal, state and local laws and
regulations.” The district court correctly recognized these provisions,
writing, “The Court finds no indication in the cited portions of the INA
that Congress intended for States to have no oversight over detention
facilities operating within their borders. Indeed, the detention facility
contracts [California] provided to the Court expressly contemplate
compliance with state and local law.” California I, 314 F. Supp. 3d at
1091 (citations omitted).
           UNITED STATES V. STATE OF CALIFORNIA            37

demonstrate any intent, let alone “clear and manifest,” that
Congress intended to supersede this authority. The district
court was correct when it concluded, “Given the Attorney
General’s power to conduct investigations related to state
law enforcement—a power which [the United States]
concedes—the Court does not find this directive in any way
constitutes an obstacle to the federal government’s
enforcement of its immigration laws or detention scheme.”
California I, 314 F. Supp. 3d at 1091–92 (citation omitted).

III.      SB 54

    We now reach the most contentious of the three
challenged laws, SB 54, which, the United States contends,
“seeks to impede the enforcement of federal immigration
laws by manipulating the overlap between state criminal
enforcement and federal immigration enforcement.”

       A. Preemption

    The United States argues that SB 54 unlawfully obstructs
the enforcement of federal immigration laws. It focuses on
a provision of the law that prohibits California law
enforcement agencies from “[t]ransfer[ring] an individual to
immigration authorities unless authorized by a judicial
warrant or judicial probable cause determination.” Cal.
Gov’t Code § 7284.6(a)(4). It notes that the INA provides
that “[o]n a warrant issued by the Attorney General, an alien
may be arrested and detained pending a decision on whether
the alien is to be removed from the United States.” 8 U.S.C.
§ 1226(a) (emphasis added). It therefore concludes that
“California has no authority to demand a judicial warrant
that Congress chose not to require. . . . By prohibiting
transfers of custody within secure areas of local jails in the
absence of a judicial warrant, California prevents federal
38       UNITED STATES V. STATE OF CALIFORNIA

officers from obtaining custody through a safe and peaceful
transfer.”

    We have no doubt that SB 54 makes the jobs of federal
immigration authorities more difficult. The question,
though, is whether that constitutes a “[c]onflict in technique”
that is impermissible under the doctrine of obstacle
preemption. Arizona II, 567 U.S. at 406 (alteration in
original).

    The United States relies in part on our opinion in Oregon
Prescription Drug Monitoring Program v. DEA, 860 F.3d
1228 (9th Cir. 2017), but that case is easily distinguished.
There, a federal agency issued statutorily authorized
subpoenas to a state agency, and the latter sought a
declaration that it need not respond because of a state statute
requiring “a valid court order” in all cases in which a
subpoena is issued. Id. at 1231–32, 1236. We concluded
that the state statute “stands as an obstacle to the full
implementation of the [federal statute] because it ‘interferes
with the methods by which the federal statute was designed
to reach [its] goal.’” Id. at 1236 (second alteration in
original) (quoting Gade, 505 U.S. at 103 (plurality opinion)).
Here, by contrast, neither an administrative warrant issued
by federal authorities nor any other provision of law
identified by the United States compels any action by a state
or local official. With the exception of § 1373(a), discussed
below, the various statutory provisions to which the United
States points direct federal activities, not those of state or
local governments. See 8 U.S.C. §§ 1226, 1231.

   We cannot simply assume that Congress impliedly
mandated that state and local governments would act in
accordance with these statutes. Even if Congress had every
expectation that they would, and opted not to codify its belief
based on the presumption that states would conduct their law
            UNITED STATES V. STATE OF CALIFORNIA                         39

enforcement activities in concert with federal immigration
efforts, it is a state’s historic police power—not
preemption—that we must assume, unless clearly
superseded by federal statute. See Arizona II, 567 U.S. at
400. 11 As California notes, “There is [] nothing in the federal
regulatory scheme requiring States to alert federal agents
before releasing a state or local inmate.” The Fifth Circuit
has aptly noted that

         [f]ederal law does not suggest the intent—let
         alone a “clear and manifest” one—to prevent
         states from regulating whether their localities
         cooperate in immigration enforcement.
         Section 1357 does not require cooperation at
         all.    And the savings clause allowing
         cooperation without a 287(g) agreement
         indicates that some state and local regulation
         of cooperation is permissible.

City of El Cenizo v. Texas, 890 F.3d 164, 178 (5th Cir. 2018)
(citations omitted) (citing 8 U.S.C. § 1357(g)(9)–(10)). 12


    11
        A state’s ability to regulate its internal law enforcement activities
is a quintessential police power. See United States v. Morrison, 529 U.S.
598, 618 (2000) (“[W]e can think of no better example of the police
power, which the Founders denied the National Government and reposed
in the States, than the suppression of violent crime and vindication of its
victims.”).

    12
       The United States points out that City of El Cenizo “upheld a state
enactment that merely required state and local officials to cooperate with
requests by federal officials,” as opposed to California’s efforts “to
disrupt the federal scheme.” But this distinction does not alter the Fifth
Circuit’s conclusion regarding the ability of states and localities to
regulate the extent to which they cooperate with federal immigration
authorities.
40        UNITED STATES V. STATE OF CALIFORNIA

    In short, SB 54 does not directly conflict with any
obligations that the INA or other federal statutes impose on
state or local governments, because federal law does not
actually mandate any state action (again, with the exception
of § 1373, discussed below).

     But that does not resolve the lingering issue of obstacle
preemption. The United States notes that SB 54 requires
federal officers to, “in effect, stake out a jail and seek to
make a public arrest. . . . Arrests of aliens in public settings
generally require five officers and present risks to the
arresting officer and the general public.” It contends that
“Congress did not contemplate that, as a consequence of
letting state detention proceed first, federal officers who
sought to detain an alien for immigration purposes would
need to race to the front of a local detention facility and seek
to effectuate an arrest before the alien manages to escape.”
Compounding the problem, the United States further claims,
are provisions of SB 54 that preclude agencies from
providing personal information and release dates to
immigration authorities.           See Cal. Gov’t Code
§ 7284.6(a)(1)(C)–(D). “So not only would California
require DHS to stake out jails to detain aliens upon their
release,” the United States continues, “but California would
require DHS to do so indefinitely because the agency would
not otherwise know if and when any given alien would be
released.”

   The district court concluded that this frustration does not
constitute obstacle preemption:

       California’s decision not to assist federal
       immigration enforcement in its endeavors is
       not an “obstacle” to that enforcement effort.
       [The United States’] argument that SB 54
       makes immigration enforcement far more
           UNITED STATES V. STATE OF CALIFORNIA                      41

         burdensome begs the question: more
         burdensome than what? The laws make
         enforcement more burdensome than it would
         be if state and local law enforcement
         provided immigration officers with their
         assistance. But refusing to help is not the
         same as impeding. If such were the rule,
         obstacle preemption could be used to
         commandeer state resources and subvert
         Tenth Amendment principles.

California I, 314 F. Supp. 3d at 1104. 13 We agree. Even if
SB 54 obstructs federal immigration enforcement, the
United States’ position that such obstruction is unlawful runs
directly afoul of the Tenth Amendment and the
anticommandeering rule.

    B. The Tenth Amendment and Anticommandeering
       Rule

    “The Constitution . . . ‘confers upon Congress the power
to regulate individuals, not States.’” Murphy v. NCAA,
138 S. Ct. 1461, 1476 (2018) (quoting New York v. United
States, 505 U.S. 144, 166 (1992)). Under the Tenth
Amendment and other provisions of the Constitution, “the
Federal Government may not compel the States to

    13
        The Seventh Circuit has conducted a similar analysis: “[T]he
Attorney General repeatedly characterizes the issue as whether localities
can be allowed to thwart federal law enforcement. That is a red herring.
. . . [N]othing in this case involves any affirmative interference with
federal law enforcement at all, nor is there any interference whatsoever
with federal immigration authorities.” City of Chicago v. Sessions,
888 F.3d 272, 282 (7th Cir. 2018), vacated in part on other grounds, No.
17-2991, 2018 WL 4268817 (7th Cir. June 4, 2018).
42          UNITED STATES V. STATE OF CALIFORNIA

implement, by legislation or executive action, federal
regulatory programs.” Printz v. United States, 521 U.S. 898,
925 (1997).

    Ultimately, we conclude that the specter of the
anticommandeering rule distinguishes the case before us
from the preemption cases on which the United States relies.
Those cases concerned state laws that affirmatively
disrupted federal operations by mandating action (or
inaction) contrary to the status quo. 14 In each, a state statute

     14
        See Arizona II, 567 U.S. at 393–94 (considering four provisions
of state law, including “[t]wo [that] create new state offenses” and two
that “give specific arrest authority and investigative duties with respect
to certain aliens to state and local law enforcement officers”); Crosby,
530 U.S. at 366 (“The issue is whether the Burma law of the
Commonwealth of Massachusetts, restricting the authority of its
agencies to purchase goods or services from companies doing business
with Burma, is invalid under the Supremacy Clause of the National
Constitution owing to its threat of frustrating federal statutory
objectives.” (footnote omitted)); Lockridge, 403 U.S. at 276 (exploring
“the extent to which the maintenance of a general federal law of labor
relations combined with a centralized administrative agency to
implement its provisions necessarily supplants the operation of the more
traditional legal processes in this field”); Nash, 389 U.S. at 236 (“The
crucial question presented here is whether a State can refuse to pay its
unemployment insurance to persons solely because they have preferred
unfair labor practice charges against their former employer.”); Paul,
373 U.S. at 133–34 (assessing a state statute that “gauge[d] the maturity
of avocados by oil content,” where federal law “gauge[d] the maturity of
avocados grown in Florida by standards which attribute no significance
to oil content”); Hines, 312 U.S. at 59 (“This case involves the validity
of an Alien Registration Act adopted by the Commonwealth of
Pennsylvania.”); Davis, 161 U.S. at 283 (determining that “an attempt,
by a State, to define [the] duties or control the conduct of [the] affairs [of
national banks] is absolutely void, wherever such attempted exercise of
authority expressly conflicts with the laws of the United States, and
either frustrates the purpose of the national legislation or impairs the
efficiency of these agencies of the Federal government to discharge the
           UNITED STATES V. STATE OF CALIFORNIA                         43

affirmatively instituted a regulatory scheme that conflicted
with federal law, either by commission (for example, by
applying differing standards or mandating affirmative action
irreconcilable with federal law) or omission (by demanding
inaction that directly conflicted with federal requirements).
The solution to avoid conflict preemption was the same:
invalidate the state enactment. In each case, the status quo
would return—either no future conflicting action would be
taken, or active compliance with federal law would
recommence—and federal activity would no longer be
obstructed.

    Here, by contrast, invalidating SB 54 would not prevent
obstruction of the federal government’s activities, because
the INA does not require any particular action on the part of
California or its political subdivisions. Federal law provides
states and localities the option, not the requirement, of
assisting federal immigration authorities. SB 54 simply
makes that choice for California law enforcement agencies.

    The United States’ primary argument against SB 54 is
that it forces federal authorities to expend greater resources
to enforce immigration laws, but that would be the case
regardless of SB 54, since California would still retain the
ability to “decline to administer the federal program.” New
York, 505 U.S. at 177. As the Supreme Court recently
rearticulated in Murphy, under the anticommandeering rule,
“Congress cannot issue direct orders to state legislatures,”
138 S. Ct. at 1478, and the Court’s earlier decision in New


duties, for the performance of which they were created”). Leslie Miller,
Gartrell Construction, Tarble’s Case, and Neagle featured similarly
affirmative disruptions of federal law; their specific facts are explored in
our discussion of AB 103 and preemption.
44         UNITED STATES V. STATE OF CALIFORNIA

York underscored that the rule also permits a state’s refusal
to adopt preferred federal policies. See 505 U.S. at 161–62.
Even in the absence of SB 54, Congress could not “impress
into its service—and at no cost to itself—the police officers
of the 50 States.” Printz, 521 U.S. at 922. 15

    Federal schemes are inevitably frustrated when states opt
not to participate in federal programs or enforcement efforts.
But the choice of a state to refrain from participation cannot
be invalid under the doctrine of obstacle preemption where,
as here, it retains the right of refusal. Extending conflict or
obstacle preemption to SB 54 would, in effect, “dictate[]
what a state legislature may and may not do,” Murphy,
138 S. Ct. at 1478, because it would imply that a state’s
otherwise lawful decision not to assist federal authorities is
made unlawful when it is codified as state law.

    We also find no constitutional infirmity in the specific
provisions of SB 54 that govern the exchange of information
with federal immigration authorities. See Cal. Gov’t Code
§ 7284.6(a)(1)(C)–(D)      (prohibiting   California    law
enforcement agencies from “[p]roviding information
regarding a person’s release date or responding to requests
for notification by providing release dates or other
information unless that information is available to the

     15
        The United States suggests that these principles do not extend here
because “both sovereigns [are] regulat[ing] private individuals,” and the
Supreme Court has held that it “is incorrect” to “assume that the Tenth
Amendment limits congressional power to pre-empt or displace state
regulation of private activities affecting interstate commerce.” Hodel v.
Va. Surface Mining & Reclamation Ass’n, 452 U.S. 264, 289–90 (1981).
But although the INA and SB 54 both implicate noncitizens—private
actors—SB 54 governs how California and its localities can interact with
the federal government, not the activities of private individuals, and so
Hodel is inapposite.
         UNITED STATES V. STATE OF CALIFORNIA              45

public,” and “[p]roviding personal information . . . about an
individual, including, but not limited to, the individual’s
home address or work address unless that information is
available to the public”). These two subparts only concern
the exchange of information, and the Supreme Court has
implied the existence of a Tenth Amendment exception for
reporting requirements. See Printz, 521 U.S. at 917–18
(distinguishing between federal statutes that “require only
the provision of information to the Federal Government” and
those that “force[ the] participation of the States’ executive
in the actual administration of a federal program”).

    The United States relies on Reno v. Condon, which
upheld against Tenth Amendment attack a federal statute
that “regulate[d] the disclosure and resale of personal
information contained in the records of state DMVs”
because it did “not require the States in their sovereign
capacity to regulate their own citizens” and instead
“regulate[d] the States as the owners of data bases.”
528 U.S. 141, 143, 151 (2000). But the Supreme Court
recently explained,

       The anticommandeering doctrine does not
       apply when Congress evenhandedly
       regulates an activity in which both States and
       private actors engage.

       That principle formed the basis for the
       Court’s decision in Reno v. Condon, which
       concerned a federal law restricting the
       disclosure and dissemination of personal
       information provided in applications for
       driver’s licenses. The law applied equally to
       state and private actors. It did not regulate
46       UNITED STATES V. STATE OF CALIFORNIA

        the States’ sovereign authority to “regulate
        their own citizens.”

Murphy, 138 S. Ct. at 1478–79 (citation omitted) (quoting
Reno, 528 U.S. at 151). Here, by contrast, it is the state’s
responsibility to help enforce federal law, and not conduct
engaged in by both state and private actors, that is at issue.
We therefore conclude that Murphy’s reading of Reno
suggests that the latter is not applicable here.

    SB 54 may well frustrate the federal government’s
immigration enforcement efforts. However, whatever the
wisdom of the underlying policy adopted by California, that
frustration is permissible, because California has the right,
pursuant to the anticommandeering rule, to refrain from
assisting with federal efforts. The United States stresses
that, in crafting the INA, Congress expected cooperation
between states and federal immigration authorities. That is
likely the case. But when questions of federalism are
involved, we must distinguish between expectations and
requirements. In this context, the federal government was
free to expect as much as it wanted, but it could not require
California’s cooperation without running afoul of the Tenth
Amendment.

     C. Intergovernmental Immunity

   The Government also argues that SB 54 violates the
doctrine of intergovernmental immunity.

   The district court correctly rejected that argument. See
California I, 314 F. Supp. 3d at 1110. In North Dakota, the
Supreme Court endorsed “a functional approach to claims of
governmental immunity, accommodating of the full range of
each sovereign’s legislative authority and respectful of the
primary role of Congress in resolving conflicts between the
         UNITED STATES V. STATE OF CALIFORNIA             47

National and State Governments.” 495 U.S. at 435 (plurality
opinion). A finding that SB 54 violates the doctrine of
intergovernmental immunity would imply that California
cannot choose to discriminate against federal immigration
authorities by refusing to assist their enforcement efforts—a
result that would be inconsistent with the Tenth Amendment
and the anticommandeering rule.

   D. Section 1373

    Lastly, the United States contends that 8 U.S.C. § 1373
directly prohibits SB 54’s information-sharing restrictions.

    Section 1373 provides that “a Federal, State, or local
government entity or official may not prohibit, or in any way
restrict, any government entity or official from sending to,
or receiving from, [DHS] information regarding the
citizenship or immigration status, lawful or unlawful, of any
individual.” 8 U.S.C. § 1373(a). SB 54, in turn, expressly
permits the sharing of such information, and so does not
appear to conflict with § 1373. See Cal. Gov’t Code
§ 7284.6(e) (“This section does not prohibit or restrict any
government entity or official from sending to, or receiving
from, federal immigration authorities, information regarding
the citizenship or immigration status, lawful or unlawful, of
an individual . . . pursuant to Section[] 1373.”). But the
United States argues that § 1373 actually applies to more
information than just immigration status, and hence that
SB 54’s prohibition on sharing other information creates a
direct conflict.

    We disagree. Although the United States contends that
“whether a given alien may actually be removed or detained
by federal immigration authorities is, at a minimum,
information regarding that alien’s immigration status,” the
phrase “information regarding the citizenship or
48         UNITED STATES V. STATE OF CALIFORNIA

immigration status, lawful or unlawful, of any individual” is
naturally understood as a reference to a person’s legal
classification under federal law, as the district court
concluded. See California I, 314 F. Supp. 3d at 1102 (“[T]he
plain meaning of Section 1373 limits its reach to information
strictly pertaining to immigration status (i.e. what one’s
immigration status is) and does not include information like
release dates and addresses.”). 16 Phrases like “regarding”
may generally have “a broadening effect, ensuring that the
scope of a provision covers not only its subject but also
matters relating to that subject,” Lamar, Archer & Cofrin,
LLP v. Appling, 138 S. Ct. 1752, 1759–60 (2018), but if the
term “regarding” were “taken to extend to the furthest stretch
of its indeterminacy, then for all practical purposes pre-

     16
       This is consistent with our decision in Steinle v. City and County
of San Francisco, in which we determined that “[t]he statutory text [of
§ 1373(a)] does not include release-date information. It includes only
‘information regarding’ ‘immigration status,’ and nothing in [§ 1373(a)]
addresses information concerning an inmate’s release date.” No.
17-16283, slip op. at 16 (9th Cir. Mar. 25, 2019). Several district courts
have reached similar conclusions regarding § 1373’s circumscribed
scope. See, e.g., City and County of San Francisco v. Sessions, 349 F.
Supp. 3d 924, 968 (N.D. Cal. 2018) (“Given my interpretation of Section
1373, limiting it to information relevant to citizenship or immigration
status not including release date information, it is clear [SB 54] complies
with Section 1373.”), appeal docketed, No. 18-17308 (9th Cir. Dec. 4,
2018); City of Philadelphia v. Sessions, 309 F. Supp. 3d 289, 333 (E.D.
Pa. 2018) (“The phrase ‘citizenship or immigration status,’ plainly
means an individual’s category of presence in the United States—e.g.,
undocumented, refugee, lawful permanent resident, U.S. citizen, etc.—
and whether or not an individual is a U.S. citizen, and if not, of what
country. The phrase ‘information regarding’ includes only information
relevant to that inquiry. When an individual will be released from a
particular City facility, cannot be considered ‘information regarding’ his
immigration status.”), aff’d in part, vacated in part on other grounds sub
nom. City of Philadelphia v. Attorney Gen., 916 F.3d 276 (3d Cir. 2019).
           UNITED STATES V. STATE OF CALIFORNIA                       49

emption would never run its course, for ‘[r]eally,
universally, relations stop nowhere.’” N.Y. State Conference
of Blue Cross & Blue Shield Plans v. Travelers Ins. Co.,
514 U.S. 645, 655 (1995) (alteration in original) (quoting H.
James, Roderick Hudson xli (New York ed., World’s
Classics 1980)). 17

    Congress has used more expansive phrases in other
provisions of Title 8 when intending to reach broader swaths
of information. See, e.g., 8 U.S.C. § 1360(a) (mandating the
inclusion of “such other relevant information as the Attorney
General shall require as an aid” to the creation of a central
index of noncitizens entering the country); id. § 1360(b)
(“Any information in any records kept by any department or
agency of the Government as to the identity and location of
aliens in the United States shall be made available to the
Service upon request.”). The United States claims that
§ 1373(c) demonstrates the extensive reach of § 1373(a), as
unlike the latter, the former does not use the term
“regarding” but instead refers simply and explicitly to “the
citizenship or immigration status of any individual.” Id.
§ 1373(c). But the fact that subpart (c) only concerns itself
with immigration status suggests, given § 1373’s focus on
reciprocal communication between states and the federal
government, that immigration status is the extent of
subpart (a)’s reach as well. 18


    17
       Indeed, the range of facts that might have some connection to
federal removability or detention decisions is extraordinarily broad. See,
e.g., 8 U.S.C. § 1182 (listing various admissibility considerations,
including vaccination history, education, financial resources, and
membership in “the Communist or any other totalitarian party”).
    18
       We note that a congressional report concerning a statute with
similar language to § 1373 indicated that it “provides that no State or
50         UNITED STATES V. STATE OF CALIFORNIA

    The United States also relies heavily on an Information
Bulletin issued by the California Department of Justice in
June 2014, which read in part that “law enforcement officials
may provide information to ICE, including notification of
the date that an individual will be released, as requested on
an immigration detainer form. Federal law provides that
state and local governments may not be prohibited from
providing information to or receiving information from
ICE.” The United States contends that California’s “limited
view of the scope of [§ 1373] contradicts the longstanding
views . . . of the California Attorney General.” But the
Information Bulletin attempted to summarize both federal
law and California’s then-governing TRUST Act, not the
laws at issue today. And at any rate, the previous
conclusions of the California Attorney General do not
change the plain text and meaning of § 1373; that the
California Department of Justice might have been incorrect
then does not mean that its revised interpretation is incorrect
now.

   In summation, the district court correctly concluded that
“Section 1373 and the information sharing provisions of SB

local government entity shall prohibit, or in any way restrict, any entity
or official from sending to or receiving from the [federal government]
information regarding the immigration status of an alien or the presence,
whereabouts, or activities of illegal aliens.” H.R. Rep. No. 104-725, at
383 (1996) (Conf. Rep.), as reprinted in 1996 U.S.C.C.A.N. 2649, 2771.
But the fact that the report distinguished between the two categories—
“information regarding the immigration status of an alien or the
presence, whereabouts, or activities”—suggests that “information
regarding the immigration status” does not include “the presence,
whereabouts, or activities” of noncitizens. And in any event,
“Congress’s ‘authoritative statement is the statutory text, not the
legislative history.’” Whiting, 563 U.S. at 599 (quoting Exxon Mobil
Corp. v. Allapattah Servs., Inc., 545 U.S. 546, 568 (2005)).
           UNITED STATES V. STATE OF CALIFORNIA                       51

54 do not directly conflict.” California I, 314 F. Supp. 3d at
1104. 19

IV.      Winter Factors

    California argues that the three other Winter factors—
irreparable harm, the balance of the equities, and the public
interest, 555 U.S. at 20—provide an alternative basis for
affirming the district court’s denial of a preliminary
injunction. See Big Country Foods, Inc. v. Bd. of Educ.,
868 F.2d 1085, 1088 (9th Cir. 1989) (concluding that a
district court’s denial of a motion for a preliminary
injunction “may [be] affirm[ed] on any ground supported by
the record”). Because we agree with the district court that
the United States is unlikely to succeed on the merits of its
challenges to AB 450’s employee-notice provisions and
SB 54, we consider these factors only as applied to the
provision of AB 103 that imposes an impermissible burden
on the federal government.

    In granting the United States’ motion to enjoin the two
invalidated provisions of AB 450, the district court
“presume[d] that [the United States] will suffer irreparable
harm based on the constitutional violations.” California I,
314 F. Supp. 3d at 1112. This conclusion was consistent
with our previous recognition that preventing a violation of

     19
        Because we agree with the district court’s conclusion, we need not
address whether § 1373 is itself unlawful, though we note that various
district courts have questioned its constitutionality. See, e.g., City and
County of San Francisco v. Sessions, 349 F. Supp. 3d 924, 949–53 (N.D.
Cal. 2018), appeal docketed, No. 18-17308 (9th Cir. Dec. 4, 2018); City
of Chicago v. Sessions, 321 F. Supp. 3d 855, 873 (N.D. Ill. 2018); City
of Philadelphia v. Sessions, 309 F. Supp. 3d 289, 329–31 (E.D. Pa.
2018), aff’d in part, vacated in part on other grounds sub nom. City of
Philadelphia v. Attorney Gen., 916 F.3d 276 (3d Cir. 2019).
52        UNITED STATES V. STATE OF CALIFORNIA

the Supremacy Clause serves the public interest. See, e.g.,
Arizona I, 641 F.3d at 366 (“We have found that ‘it is clear
that it would not be equitable or in the public’s interest to
allow the state . . . to violate the requirements of federal law,
especially when there are no adequate remedies
available. . . . In such circumstances, the interest of
preserving the Supremacy Clause is paramount.’”
(alterations in original) (quoting Cal. Pharmacists Ass’n v.
Maxwell-Jolly, 563 F.3d 847, 852–53 (9th Cir. 2009))); Am.
Trucking Ass’ns v. City of Los Angeles, 559 F.3d 1046,
1059–60 (9th Cir. 2009) (determining that “the balance of
equities and the public interest [] weigh in favor of a
preliminary injunction” against a likely preempted
ordinance).

     Nevertheless, California argues that “[t]he balance of
equities and public interest weigh strongly against enjoining
[its] laws during the pendency of litigation” because “a
preliminary injunction here would lead to significant,
concrete harm to the public.” At the district court, California
claimed that “the Legislature passed AB 103 in reaction to
growing concerns of egregious conditions in facilities
housing civil detainees,” California I, 314 F. Supp. 3d at
1090–91—a conclusion supported in detail by amici curiae,
including the National Health Law Program and the
Immigrant Legal Resource Center. Moreover, we note that
California retains an historic—and, since the federal
government’s contracts with immigration detainee facilities
explicitly contemplate the application of state regulations,
undisputed—authority to regulate the conditions of
detainees housed within its borders. By contrast, other than
relying on general pronouncements that a Supremacy Clause
violation alone constitutes sufficient harm to warrant an
injunction, the United States did not present compelling
evidence that AB 103 inspections conducted by the
             UNITED STATES V. STATE OF CALIFORNIA                     53

California Attorney General harmed facilities’ detention
operations. Rather, the only evidence of AB 103’s
burdensome effect is conclusory assertions made by a DHS
official in a declaration and deposition. 20 Neither he nor the
United States provided any indication, even an estimate, of
the actual costs imposed by AB 103 or the number of ICE
officers forced to assist in the extra inspection efforts, or any
quantification whatsoever of the enactment’s burden. The
United States’ complaint in this action did not even plead
that the statute imposes an economic or operational burden
on DHS or anyone else.

    We are not prepared, in the first instance, to affirm the
district court’s denial of a preliminary injunction as to

    20
         The relevant deposition transcript reads as follows:

           [I]t’s going to require yet another inspection that we
           think is unnecessary, because these are federal
           contracts, these are federal prisoners detained under
           federal authority. We have our own set of standards.
           We certainly don’t believe there should be any
           inspections to talk about due process of people that are
           in federal custody, under federal authority, conditions
           of confinement when we have our own set of standards
           which is much higher than most states.

           So there’s this general feeling that this is—it’s
           burdensome, that they’re going to be required to pull
           resources to do these inspections, when we have
           numerous inspections already at these facilities from
           various different components.

           So again, it’s—it’s talk of burdensomeness—right?—
           extra work, pulling people from their duties to host
           these things and gather documents and paperwork and
           making people available for interviews and so forth.
54         UNITED STATES V. STATE OF CALIFORNIA

AB 103’s burdensome provision based on these
considerations. However, on remand, we encourage the
district court to reexamine the equitable Winter factors in
light of the evidence in the record.

                         CONCLUSION

    We conclude that the district court correctly determined
that the United States was unlikely to succeed on the merits
of its challenges to AB 450’s employee-notice provisions
and SB 54, and therefore AFFIRM its denial of a preliminary
injunction as to these enactments. We also AFFIRM the
denial as to those provisions of AB 103 that duplicate
preexisting inspection requirements. But because we
conclude      that     California     Government       Code
section 12532(b)(1)(C) both discriminates against and
impermissibly burdens the federal government, we
REVERSE the district court’s denial of the United States’
motion as to this provision and REMAND for further
proceedings consistent with this opinion.21




    21
       Finally, we grant the State of Michigan’s motion to withdraw from
an amicus brief in support of the United States.
