 United States Court of Appeals
         FOR THE DISTRICT OF COLUMBIA CIRCUIT



Argued March 29, 2017             Decided November 28, 2017

                        No. 16-5194

              LAURA HOLMES AND PAUL JOST,
                     APPELLANTS

                             v.

              FEDERAL ELECTION COMMISSION,
                        APPELLEE


        On Certification of a Constitutional Question
           from the United States District Court
                for the District of Columbia
                    (No. 1:14-cv-01243)


    Allen Dickerson argued the cause and filed the briefs for
appellants. Owen D. Yeates entered an appearance.

    Erin Chlopak, Acting Assistant General Counsel, Federal
Election Commission, argued the cause for appellee. With her
on the brief were Lisa J. Stevenson, Deputy General Counsel,
Kevin Deeley, Associate General Counsel, and Steve N. Hajjar
and Charles Kitcher, Attorneys.

    J. Gerald Hebert, Fred Wertheimer, and Donald J. Simon
were on the brief for amici curiae Campaign Legal Center and
Democracy 21 in support of appellee.
                               1
    Before: GARLAND, Chief Judge, and HENDERSON,
ROGERS, TATEL, BROWN ∗, GRIFFITH, KAVANAUGH,
SRINIVASAN, MILLETT, PILLARD, and WILKINS, Circuit Judges.

    Opinion for the Court filed by Circuit Judge SRINIVASAN.

    SRINIVASAN, Circuit Judge:         The Federal Election
Campaign Act imposes limits on the amounts that an individual
may contribute to a candidate for federal office. 52 U.S.C.
§ 30116(a)(1)(A). Those contribution ceilings, known as
FECA’s base limits, aim to prevent the appearance or actuality
of corruption associated with large campaign contributions to
federal office holders and candidates.

     In 2014, FECA’s base limits permitted contributions of up
to $2,600 to a candidate in each election in which she
competed. So, for instance, if a candidate prevailed in a
primary election and then competed in the general election, a
donor could have contributed $2,600 to her for the primary and
another $2,600 for the general. The same $2,600 ceiling would
also have applied to any runoff election in which the candidate
took part.

     The plaintiffs in this case wished to make contributions to
a candidate in the general election in amounts exceeding the
$2,600 per-election limit. In particular, they sought to forgo
making any contributions at all in the primary election but then
effectively to carry over to the general election the amount they
could have donated in the primary. That would have enabled
them to contribute $5,200 to a candidate in the general election
alone, double the applicable limit for that election.


    ∗
       Circuit Judge Brown was a member of the en banc court but
retired before issuance of this opinion.
                               2
     Prohibited by FECA from doing so, plaintiffs brought an
action challenging the constitutionality of the statute’s base
limits on individual contributions to candidates. According to
plaintiffs, FECA violates their First Amendment rights by
allowing separate contributions to a candidate in the primary
and general elections of $2,600 each, but disallowing a
contribution in a corresponding total amount of $5,200 if
confined to the general election alone.

     Plaintiffs’ argument amounts to a challenge to Congress’s
choice to structure the base contribution limits for individuals
as per-election ceilings. When establishing those limits,
Congress had to pick some temporal frame of reference: a
contribution ceiling, to be effective, must specify not only a
maximum contribution amount (e.g., $2,600) but also a
timeframe in which that amount may be expended (e.g., $2,600
in each election). Plaintiffs, in contending that they must be
permitted to contribute twice the maximum amount in one
(general) election if they skip any contribution in a different
(primary) election, necessarily contest Congress’s choice of a
per-election ceiling.

     We decline plaintiffs’ invitation to upend the per-election
structure of FECA’s base limits on individual contributions to
candidates. The Supreme Court, in Buckley v. Valeo, 424 U.S.
1 (1976), rejected a constitutional challenge to those ceilings,
and that holding remains undisturbed. The Court explained
that, as long as a contribution limit is not so low as to prevent
candidates from mounting effective campaigns, the judiciary
would generally defer to Congress’s determination of the
limit’s precise amount. We conclude the same is true of
Congress’s intertwined choice of the timeframe in which that
amount may be contributed. As a result, we reject plaintiffs’
challenge to Congress’s decision to fashion FECA’s base
contribution limits for individuals as per-election ceilings.
                               3
                               I.

     The Federal Election Campaign Act (FECA) restricts the
amounts that an individual may contribute to any federal
candidate or political (e.g., party) committee. 52 U.S.C.
§ 30116(a)(1). Those limits on a person’s contributions to a
particular candidate or political committee are referred to as
FECA’s “base” limits, as distinguished from the statute’s
“aggregate” limits on a person’s overall contributions to all
candidates or political committees, collectively. The Supreme
Court invalidated FECA’s aggregate limits in McCutcheon v.
FEC, 134 S. Ct. 1434 (2014), but the base limits remain intact.

     The base limits on contributions to federal candidates
operate on a per-election basis, whereas the base limits on
contributions to political committees operate on an annual
basis. 52 U.S.C. § 30116(a)(1). This case concerns the per-
election ceiling on individual contributions to candidates.

                               A.

     Originally, Congress limited an individual’s contributions
to federal candidates solely through an aggregate, $5,000
ceiling on donations “during any calendar year.” Hatch Act
Amendments of 1940, Pub. L. No. 76-753, § 13(a), 54 Stat.
767, 770. In 1974, Congress amended FECA to add the base
limits on contributions to candidates that are at issue here. See
Federal Election Campaign Act Amendments of 1974, Pub. L.
No. 93-443, § 101(a), 88 Stat. 1263, 1263.

    Those base limits differed from the original ceiling on
individual contributions to candidates in two ways. First,
whereas the original ceiling had been an aggregate limit on a
person’s collective contributions to all candidates, Congress
fashioned the base limits as a cap on the amount of
                                4
contributions to any individual candidate. Second, and of
particular relevance here, whereas the aggregate limits
operated as an annual ceiling, Congress structured the base
limits on individual contributions to candidates as a per-
election ceiling. And Congress defined an “election” to include
any “general, special, primary, or runoff election.” Federal
Election Campaign Act of 1971, Pub. L. No. 92-225 § 201, 86
Stat. 3, 8. The result was that the base limits, as enacted in
1974, imposed a $1,000 ceiling on a person’s contributions to
any given candidate in any given election. 88 Stat. at 1263.

     In 2002, Congress increased the base contribution limit to
$2,000 per election and indexed it to inflation for future cycles.
Bipartisan Campaign Reform Act of 2002, Pub. L. No. 107-
155, § 307(a), (d), 116 Stat. 81, 102-03 (codified as amended
at 52 U.S.C. § 30116(a)(1)(A), (c)). Congress also kept in
place (and increased) the aggregate limit on an individual’s
contributions to all federal candidates. See id. § 307(b)
(codified at 52 U.S.C. § 30116(a)(3)(A)). But that aggregate
ceiling, as noted, was set aside by the Supreme Court in
McCutcheon, 134 S. Ct. 1434. The Court, though, expressly
left the base limits “undisturbed.” Id. at 1451 (plurality
opinion). (Because the plurality in McCutcheon issued the
controlling opinion, see Marks v. United States, 430 U.S. 188,
193-94 (1977), we will treat that opinion as the opinion of the
Court.)

     When the Court decided McCutcheon in 2014, the base
limits, as adjusted for inflation, allowed an individual to
contribute up to $2,600 per election to a given candidate. See
134 S. Ct. at 1442. While the base limits have increased to
$2,700 in the intervening years, see Price Index Adjustments
for Contribution and Expenditure Limitations and Lobbyist
Bundling Disclosure Threshold, 82 Fed. Reg. 10,904, 10,906
(Feb. 16, 2017), we will consider $2,600 as the operative per-
                               5
election limit because 2014 is the relevant election cycle for
purposes of this case.

                               B.

     The plaintiffs in this case, Laura Holmes and Paul Jost, are
a married couple residing in Florida. In the 2014 congressional
elections, plaintiffs each supported a different candidate, one
of whom ran for a California seat and the other of whom ran
for an Iowa seat.

     Plaintiffs made no contributions to their preferred
candidates in the primary election. But they both contributed
the maximum amount then permitted by FECA, $2,600, to their
preferred candidates in the general election. And both would
have contributed an additional $2,600 in the general election if
not for FECA’s per-election contribution ceiling. Plaintiffs’
preferred candidates each lost in the general election.

     FECA enables any eligible voter to challenge the
constitutionality of the Act in federal district court. 52 U.S.C.
§ 30110. In July 2014, plaintiffs brought this action against the
Federal Election Commission. They alleged that FECA’s per-
election base contribution limit violates the First Amendment
and the equal protection component of the Fifth Amendment.
That was so, plaintiffs contended, because the per-election
limit allows contributing $2,600 to a candidate in each of the
primary and general elections but bars contributing the same
cumulative amount of $5,200 if allocated entirely to the general
election.

    FECA calls for a district court to certify non-frivolous
constitutional questions to the en banc court of appeals. 52
U.S.C. § 30110; Cal. Med. Ass’n v. FEC, 453 U.S. 182, 192
n.14 (1981). The district court determined that plaintiffs’
                                6
constitutional challenges involved “questions of settled law”
and thus did not warrant certification to our court. Holmes v.
FEC, 99 F. Supp. 3d 123, 149 (D.D.C. 2015). A panel of this
court disagreed with respect to plaintiffs’ First Amendment
claim, holding that no Supreme Court precedent squarely
addressed the “constitutionality of the Act’s per-election
structure” for contributions to candidates. Holmes v. FEC, 823
F.3d 69, 75 (D.C. Cir. 2016). The panel therefore remanded
the case to the district court to make appropriate findings of
fact and certify the relevant constitutional question to this court
sitting en banc. Id. at 76.

     On remand, the district court certified its previous factual
findings, together with the following question, for our en banc
consideration:

        When federal law limits individual contributors to
        giving $2,600 to a candidate for use in the primary
        election and $2,600 to a candidate for use in the general
        election and denies Plaintiffs the ability to give $5,200
        to a candidate solely for use in the general election,
        does it violate Plaintiffs’ rights of freedom to associate
        guaranteed by the First Amendment, U.S. Const.
        amend. I?

Am. Order, ECF No. 42. We now take up that question.

                                II.

     In Buckley v. Valeo, 424 U.S. 1 (1976), the Supreme Court
upheld FECA’s base contribution limits for individuals against
a First Amendment challenge. Plaintiffs seek to distinguish
their claim from the one denied in Buckley by arguing that the
Supreme Court did not specifically consider the validity of the
per-election structure of those limits. We conclude, however,
                               7
that the analysis in Buckley ultimately governs—and compels
rejecting—plaintiffs’ challenge to the per-election structure of
FECA’s base limits.

     In fashioning FECA’s base limits for individuals as per-
election ceilings, Congress mirrored the approach adopted by
many states:      the vast majority of states to establish
contribution ceilings for state elections have likewise opted for
a per-election format. See Amicus Br. of Campaign Legal Ctr.
18-19. In plaintiffs’ view, Congress and the states are
forbidden to make that choice. We hold otherwise.

                               A.

     In Buckley, the Supreme Court set out the standards for
judicial review of campaign-finance regulations challenged
under the First Amendment. The Court drew a distinction
between limits on a person’s expenditures for election-related
advocacy and limits on a person’s contributions to candidates
(or party committees). Restrictions on a person’s independent
expenditures must survive “strict scrutiny,” which requires that
the limitations advance a compelling governmental interest and
constitute the least restrictive means of doing so. See
McCutcheon, 134 S. Ct. at 1444; Buckley, 424 U.S. at 44-45;
Wagner v. FEC, 793 F.3d 1, 5 (D.C. Cir. 2015) (en banc).
Restrictions on a person’s campaign contributions, meanwhile,
draw “a lesser but still ‘rigorous standard of review.’”
McCutcheon, 134 S. Ct. at 1444 (quoting Buckley, 424 U.S. at
29).

    Contribution limits are subject to a more relaxed standard
because they “impose a lesser restraint on political speech”:
they “permit[] the symbolic expression of support evidenced
by a contribution but do[] not in any way infringe the
contributor’s freedom to discuss candidates and issues.” Id. at
                               8
1444 (quoting Buckley, 424 U.S. at 21). Under the applicable
standard for contribution limits, “[e]ven a significant
interference with protected rights of political association may
be sustained if the State demonstrates a sufficiently important
interest and employs means closely drawn to avoid
unnecessary abridgement of associational freedoms.” Id.
(emphasis added) (internal quotation marks omitted) (quoting
Buckley, 424 U.S. at 25); see Wagner, 793 F.3d at 5.

     Buckley, applying that “closely drawn” standard, sustained
FECA’s base limits on individual contributions to candidates
against a First Amendment challenge. At the time, FECA
imposed a $1,000 ceiling on a person’s contributions to a given
candidate in each election. See Buckley, 424 U.S. at 23. Then,
as now, the statute treated primary elections, general elections,
and runoff elections as distinct events for purposes of the per-
election contribution ceiling. See id. at 24; 52 U.S.C.
§ 30101(1)(A), § 30116(a)(1)(A), (a)(6).

     The Court found it “unnecessary to look beyond the Act’s
primary purpose—to limit the actuality and appearance of
corruption resulting from large individual financial
contributions—in order to find a constitutionally sufficient
justification for the $1,000 contribution limitation.” 424 U.S.
at 26. The Court explained that the “$1,000 contribution
limitation focuses precisely on the problem of large campaign
contributions—the narrow aspect of political association where
the actuality and potential for corruption have been
identified—while leaving persons free to engage in
independent political expression.” Id. at 28.

     The Court also rejected the contention “that the $1,000
restriction is unrealistically low because much more than that
amount would still not be enough to enable an unscrupulous
contributor to exercise improper influence over a candidate or
                                 9
officeholder, especially in campaigns for statewide or national
office.” Id. at 30. In that regard, the Court noted that FECA’s
then-existing limits on expenditures (as opposed to the limits
on contributions) were “scaled to take account of the
differences in the amounts of money required for congressional
and Presidential campaigns.” Id. at 30 n.32. While the
contribution limits might “have been structured” in a similarly
“graduated” way depending on the office sought—instead of
taking the form of a flat, $1,000 ceiling regardless of office—
“Congress’ failure to engage in such fine tuning [did] not
invalidate the legislation.” Id. at 30.

                                B.

     In light of the Supreme Court’s decision in Buckley,
plaintiffs here understandably “concede the constitutionality of
contribution limits generally.” Plaintiffs’ Opening Br. 9. They
also “do not challenge the specific dollar amount Congress has
chosen.” Id. at 12. That, too, is with good reason: the $2,600
base contribution limit applicable to plaintiffs represents an
updated version of the $1,000 ceiling sustained in Buckley.

     Plaintiffs instead characterize their claim as contesting
“only the manner in which the total amount of money that
Congress has said will not corrupt a candidate is split between
the primary and general elections.” Id. at 12-13. That claim,
in plaintiffs’ view, remains viable after Buckley. Plaintiffs’
elaboration of their claim proceeds in the following steps.

     First, plaintiffs describe FECA as imposing an “overall
$5,200 cap on contributions,” which they conceive to be the
statute’s “base limit.” Id. at 9, 19. Second, they contend that
the statute’s “artificial bifurcation” of that ostensible limit into
separate, $2,600 ceilings for the primary and general elections
must itself combat corruption in a manner satisfying the
                                10
“closely drawn” standard applicable to contribution limits.
Plaintiffs’ Reply Br. 1, 12. Third, plaintiffs argue that the
bifurcation between the primary and general elections cannot
be sustained because the statute permits—and hence considers
non-corrupting—a total of $5,200 in contributions over those
two elections. As a result, plaintiffs submit, they cannot be
forced to divide their desired $5,200 contribution between the
primary and general elections.

     Plaintiffs’ argument falls short at every step. Their
challenge ultimately seeks to invalidate the per-election
structure of FECA’s base contribution limits for individuals.
Plaintiffs would prefer a version of an election-cycle ceiling (of
$5,200) to the per-election ceiling (of $2,600) chosen by
Congress. But just as the Supreme Court in Buckley declined
to overturn Congress’s choice of a $1,000 contribution ceiling
over a higher ceiling, we see no basis to upset Congress’s
choice of a per-election ceiling over a per-cycle ceiling.

                                1.

     The starting premise of plaintiffs’ argument is that FECA
imposes a $5,200 base limit on a person’s contributions to a
candidate, which the statute, as plaintiffs see things, artificially
bifurcates between the primary and general elections.
Plaintiffs’ understanding of FECA is fundamentally mistaken.

     Contrary to plaintiffs’ account of FECA, there is no $5,200
base contribution ceiling split between the primary and general
elections. Instead, the Act by its terms establishes a $2,000
contribution limit, adjusted for inflation, which “shall apply
separately with respect to each election.”           52 U.S.C.
§ 30116(a)(1)(A), (a)(6). The statute then defines an “election”
to include a primary election or general election (and also, if
applicable, a runoff election). Id. § 30101(1)(A). As a result,
                               11
FECA does not establish any overarching $5,200 ceiling that is
then divided into separate $2,600 caps for the primary and
general elections. The statute, rather, simply imposes a $2,600
base limit for each of those (and any other) elections.

     To be sure, the upshot of the $2,600 per-election base limit
is that, if a person contributes the maximum amount to a
candidate who competes in both a primary and a general
election, the combined contributions would equal $5,200. The
Supreme Court thus has referred to a “$5,200 base limit” as
shorthand for the total contributions permitted across a primary
and general election together. McCutcheon, 134 S. Ct. at 1452.
But the Court specifically understood that the $5,200 figure is
only an extrapolation of the statute’s actual base limit, i.e.,
$2,600 per election: the Court explained that FECA’s “base
limits . . . permit an individual to contribute up to $2,600 per
election to a candidate ($5,200 total for the primary and general
elections).” Id. at 1442 (emphasis added).

     The absence of any $5,200 base limit in the statute
becomes particularly evident when one considers the potential
implications of a runoff election.         That is hardly an
unpredictable occurrence. In the 2014 election cycle alone, 15
congressional races included at least one runoff election, and
in the decade culminating in the 2014 cycle, 95 congressional
races involved a runoff election. Holmes, 99 F. Supp. 3d at
133. Because FECA’s $2,600 per-election ceiling applies
separately to any runoff election, the permissible contributions
to a candidate who competes in a primary, runoff, and general
election would reach $7,800—not just $5,200—over the course
of an election cycle.

     The statute, in short, imposes a $2,600 per-election limit,
not any $5,200 (or $7,800) limit. Accordingly, when plaintiffs
challenge what they characterize as the “per-election division”
                               12
or “bifurcation” of the supposed $5,200 base limit, Plaintiffs’
Opening Br. 9, 13, they in fact challenge the per-election
structure of the $2,600 base limit. They would like to
contribute $5,200 to a candidate in the general election alone,
which the $2,600 per-election cap forbids them from doing.

                               2.

     Plaintiffs argue that Congress’s choice of a per-election
structure must itself advance an anti-corruption interest under
the “closely drawn” test set out in Buckley. Plaintiffs do not
dispute that the $2,600 base contribution limit, as a general
matter, serves to prevent corruption (or its appearance) in
satisfaction of that standard. But they conceive of the limit’s
per-election structure as an added restriction that must
separately promote an anti-corruption objective.

     Plaintiffs ground their understanding in the Supreme
Court’s decision in McCutcheon. There, the Court invalidated
FECA’s aggregate contribution limits, reasoning that those
ceilings afforded no additional anti-corruption benefit beyond
the base limits. The Court observed that the base limits had
been “upheld [in Buckley] as serving the permissible objective
of combatting corruption.” 134 S. Ct. at 1442. And although
the government “contend[ed] that the aggregate limits also
serve that objective,” the Court found “that the aggregate limits
do little, if anything, to address that concern.” Id. The Court
further noted that the base limits “themselves are a prophylactic
measure.” Id. at 1458. The “aggregate limits are then layered
on top, ostensibly to prevent circumvention of the base limits.”
Id. But because the aggregate limits did not in fact serve that
purpose, the “prophylaxis-upon-prophylaxis approach” they
embodied was deemed invalid. Id.
                               13
     Plaintiffs seek to draw a parallel between the per-election
structure at issue here and the aggregate limits examined in
McCutcheon. They contend that, like the aggregate limits, the
per-election structure of the base contribution ceilings “is not
closely drawn” unless it “is targeted toward a risk of corruption
that is not already addressed by the contribution limits in
general.” Plaintiffs’ Opening Br. 16. And the per-election
structure of those ceilings, plaintiffs submit, fails to advance
the anti-corruption interest in any way not already
accomplished by the base limits. Plaintiffs thus conclude that,
“like the unconstitutional aggregate limits at issue in
McCutcheon, the bifurcated [i.e., per-election] limits are
‘layered on top’ of base limits that themselves . . . combat
corruption” only indirectly, amounting to an invalid
“prophylaxis-upon-prophylaxis” approach of the kind rejected
in McCutcheon. Id. at 24.

     Plaintiffs’ effort to analogize the base limits’ per-election
structure to the aggregate ceilings considered in McCutcheon
is misconceived. The aggregate limits were an additional
constraint “layered on top” of the base limits, McCutcheon, 134
S. Ct. at 1458, and thus separately needed to serve the interest
in preventing the appearance or actuality of corruption. The
contribution ceilings’ per-election structure, by contrast, is not
layered on top of the base limits; it is an integral part of the
base limits themselves.

     A contribution limit necessarily contains two essential
ingredients: (i) a monetary cap, and (ii) a time period. A statute
simply specifying that contributions may be made “annually,”
without setting forth any monetary ceiling, would of course be
entirely ineffectual (and nonsensical): it would seemingly
allow contributions of any amount within a given year.
Likewise, a statute capping contributions at $2,600, without
identifying any associated timeframe, would be equally
                               14
ineffectual: it would seemingly allow repeated contributions
of $2,599 without end.

    To impose a meaningful contribution ceiling, then,
Congress has no choice but to specify some time period in
which donors can contribute the maximum amount. There are
a host of alternatives in that regard.

     Congress could impose an annual ceiling, as it did with
FECA’s base limits on contributions to political committees.
See id. at 1442; 52 U.S.C. § 30116(a)(1)(B)-(D). Congress
could also establish a biennial cap, as with the aggregate limits
considered in McCutcheon. Id. § 30116(a)(3). Congress could
instead fashion a limit encompassing an election cycle, as with
the per-cycle regime favored by plaintiffs and adopted by
certain states. E.g., Ariz. Rev. Stat. Ann. § 16-912(A); Md.
Code Ann., Elec. Law § 13-226(b); Vt. Stat. Ann. tit. 17,
§ 2941(a)(1)-(3). Or Congress could impose a ceiling for each
election, as with the $2,600 per-election limit we consider here,
or with the per-election caps enacted by the majority of states,
see Amicus Br. of Campaign Legal Ctr. 18-19.

     Congress’s choice of a per-election structure thus is not a
“prophylaxis-upon-prophylaxis”—a second anti-corruption
measure layered on top of the base limits. Instead, the per-
election structure is an essential ingredient of the base limits
themselves—the first layer of prophylaxis.             Unlike in
McCutcheon, then, there is no warrant for attempting to
ascertain whether the per-election timeframe of the $2,600 base
limit itself combats corruption. Rather, it is enough if that base
limit as a whole (of which its time period is an integral element)
prevents the appearance or actuality of corruption in a manner
satisfying the closely drawn standard.
                               15
     The Supreme Court’s analysis in Buckley bears out that
understanding. There, the Court applied the closely drawn
standard to the $1,000 per-election base contribution ceiling
then in existence. 424 U.S. at 24-29. The Court concluded that
the $1,000 base limit advanced the “weighty interests” in
combatting corruption or its appearance in a manner “sufficient
to justify the limited effect upon First Amendment freedoms.”
Id. at 29. The Court found “no indication” that the $1,000
ceiling established by Congress would “prevent[] candidates”
from “amassing the resources necessary for effective
advocacy.” Id. at 21; see Randall v. Sorrell, 548 U.S. 230, 247-
49 (2006) (plurality opinion) (discussing Buckley).

     Having generally sustained the base limit under the closely
drawn standard, the Court then examined whether the across-
the-board, $1,000 ceiling was too low as applied to certain
elections for which a higher ceiling would still prevent
corruption (such as campaigns for statewide or national office,
which typically require greater amounts of funding). Buckley,
424 U.S. at 30. In addressing that question, the Court did not
ask whether Congress’s choice of a flat, $1,000 limit—instead
of a graduated scheme allowing for higher ceilings for certain
elections—itself advanced the anti-corruption interest under
the closely drawn test. The Court instead explained that, once
it was “satisfied that some limit on contributions is necessary”
to address corruption, it had “no scalpel to probe, whether, say,
a $2,000 ceiling might not serve as well as $1,000.” Id.
(quoting Buckley v. Valeo, 519 F.2d 821, 842 (D.C. Cir. 1975)).
That was a “distinction[] in degree,” not a “difference[] in
kind.” Id.

     The same is true of Congress’s choice of a per-election cap
rather than a per-cycle, annual, or biennial one. Just as Buckley
did not require Congress to explain its choice of $1,000 rather
than $2,000 as itself closely drawn to preventing corruption,
                               16
we see no basis for requiring Congress to justify its choice
concerning the other essential element of a contribution limit—
its timeframe—as itself serving that interest. A contribution
ceiling, we know from Buckley, can validly promote an anti-
corruption objective, at least as long as it is not so low as to
prevent effective campaigns. If so, Congress need not justify
its exact choice as to the ceiling’s time period (or dollar
amount) with some added anti-corruption explanation.

                               3.

     Even if the per-election structure of FECA’s $2,600 base
limit need not separately advance the limit’s anti-corruption
objective, plaintiffs argue, allowing them to exceed that
amount at least would not undermine that objective. As a
result, plaintiffs reason, they should be permitted to contribute
$5,200 in the general election. They stress that the $2,600 per-
election ceiling would allow cumulative contributions of
$5,200 to a candidate who participates in both the primary and
general elections. If $5,200 in contributions across both
elections raises no undue prospect of corruption, plaintiffs ask,
then what could be the reason to disallow the same overall
contribution across the elections merely because it is paid in
the general election alone?

     Congress had a perfectly understandable reason:
Congress, needing to select some timeframe in order to
establish an effective base contribution limit, chose a per-
election structure and reasonably defined the primary and
general elections as separate events for purposes of the $2,600
ceiling.    Enforcement of the $2,600 per-election limit
necessarily means that a person cannot be allowed to contribute
twice that amount to a candidate in the general election alone.
                               17
     Plaintiffs’ challenge, though, would prohibit giving effect
to that per-election ceiling anytime a person contributes less
than $2,600 to a candidate in the primary election. Such a
person, under plaintiffs’ rationale, would be entitled to
contribute more than the $2,600 per-election cap in the general
election, up to a combined contribution of $5,200 for both the
primary and general elections. So someone who makes no
contribution in the primary could contribute the full $5,200 in
the general election, someone who gives $1,000 in the primary
could contribute the remaining $4,200 in the general election,
and so on.

     Plaintiffs’ rationale, in that fashion, would effectively
transform the per-election, $2,600 contribution limit chosen by
Congress into a per-cycle, $5,200 contribution limit, at least in
the case of a person who contributes less than $2,600 in the
primary. Plaintiffs insist that they do not desire a pure, per-
cycle structure. They observe that, while they wish to
contribute up to $5,200 in the general election, they have no
reciprocal interest in contributing up to $5,200 in the primary
election, as would also be permitted in a pure, per-cycle
regime. In other words, they seek only to backload their
desired $5,200 contribution, not frontload it.

     Regardless, plaintiffs at least seek a variant of a per-cycle
ceiling—a back-loaded adaptation—under which they can give
up to $5,200 in the general election by carrying over any
amounts that could have been (but were not) contributed in the
primary. Plaintiffs thus would displace Congress’s per-
election structure with a version of a per-cycle structure.

     We know of no reason to compel adoption of a per-cycle
ceiling instead of a per-election one (or vice versa). After all,
a contribution limit, whether structured as a per-election or per-
cycle ceiling, generally addresses the appearance and actuality
                                18
of corruption from large campaign donations. Plaintiffs make
no attempt to suggest that a per-cycle approach bears some
inherent structural advantage on that score. The many states to
have chosen per-election contribution ceilings evidently
believe otherwise. Cf. McCutcheon, 134 S. Ct. at 1451 n.7 (“It
would be especially odd to regard aggregate limits as essential
to enforce base limits when state campaign finance schemes
typically include base limits but not aggregate limits.”).

     Moreover, even if there were some ground compelling us
to transform Congress’s $2,600 per-election ceiling into a per-
cycle analogue, we could not assume that Congress necessarily
would have chosen a per-cycle cap of $5,200. Congress could
conceivably regard a one-time contribution of $5,200 in the
general (or primary) election alone to present a greater risk of
apparent or actual corruption than two distinct contributions of
$2,600 in each of the primary and general elections. For that
reason as well, we have no basis for converting FECA’s $2,600
per-election ceiling into a form of a $5,200 per-cycle ceiling.

     While those are reasons enough to reject plaintiffs’
argument, their rationale would not just call for shifting a
$2,600 per-election limit into a variant of a $5,200 per-cycle
ceiling. Their argument would ultimately support an attack on
contribution limits generally.

     To start with, in the event of a run-off election to determine
the winner of a party primary, a per-election cap of $2,600
would permit total contributions of $7,800 to a candidate who
took part in a primary, runoff, and general election. Under
plaintiffs’ argument, then, a person who made no contributions
to a candidate before the general election should be permitted
to give at least triple the limit—i.e., $7,800, not just $5,200—
in that election. Indeed, at least one state provides for runoffs
to determine the winners of both primary and general elections,
                               19
meaning that a candidate could participate in four elections in
a single cycle. Ga. Code Ann. § 21-2-501. Donors in that state,
under plaintiffs’ approach, should be able to contribute $10,400
to such a candidate in the last of the four elections if they have
made no donations to her until then.

     But the logic of plaintiffs’ theory goes further still. Their
rationale not only supports a per-cycle limit of $7,800 (or even
$10,400) rather than $5,200, but it also has no necessary
stopping point with a given election cycle. While plaintiffs
may not claim an entitlement to roll over potential
contributions from election cycle to election cycle, their theory
could support doing so.

     Consider, for instance, an incumbent congresswoman
seeking reelection for a second term. Across her two election
cycles, a $2,600 per-election ceiling would permit total
contributions to her of $10,400 (or $15,600 with one runoff
election in each cycle, or even $20,800 with two runoffs in each
cycle). For a person who made no contributions to her in her
first campaign, plaintiffs’ theory could call for allowing a
contribution of $10,400 (or $15,600, or $20,800) in the second
election cycle. And the same rationale, if pushed to its extreme,
could even encompass a single contribution of many tens of
thousands of dollars to a candidate when taking into account
the total amounts that could be donated to her over the course
of her (potentially decades-long) political career.

     Even assuming plaintiffs’ theory need not stretch that far,
their rationale does more than merely challenge the per-
election structure of FECA’s $2,600 base contribution limit. It
calls into question the enforceability of any contribution
ceiling, regardless of its timeframe. Plaintiffs’ theory assumes
a contributor’s entitlement to roll over amounts that he could
(but does not) give. If so, any contribution limit, no matter its
                              20
timeframe, must permit donations exceeding its cap if a person
withholds contributions: a per-election ceiling must allow
giving double the cap in the second election, an annual ceiling
must do the same in the second year, a per-cycle ceiling must
do likewise in the second cycle, and so forth.

    The logic of plaintiffs’ challenge therefore extends to any
contribution ceiling, not just the per-election structure chosen
by Congress for FECA’s base contribution limits for
individuals. Such a theory cannot be reconciled with Buckley’s
general approval of contribution limits as adequately suited to
combatting the appearance or actuality of corruption.

    Still, a contribution ceiling’s timeframe is not entirely
immune to challenge under the First Amendment. A limit’s
time period, like its monetary cap, cannot give rise to a
contribution ceiling so low as to “harm the electoral process by
preventing challengers from mounting effective campaigns.”
Randall, 548 U.S. at 249 (plurality opinion); see Buckley, 424
U.S. at 21.

     In Randall, the Supreme Court therefore invalidated
Vermont’s per-cycle contribution ceilings, which ranged from
$200 to $400 depending on the office. The plurality (and
controlling) opinion, noting Buckley’s refusal to scrutinize the
difference between a $1,000 and $2,000 per-election ceiling,
observed that “ordinarily we have deferred to the legislature’s
determination of such matters.” 548 U.S. at 248. But
contribution limits can be “too low and too strict” if they
“prevent candidates from ‘amassing the resources necessary
for effective [campaign] advocacy’” or “magnify the
advantages of incumbency to the point where they put
challengers to a significant disadvantage.” Id. at 248 (quoting
Buckley, 424 U.S. at 21). The per-cycle ceiling examined in
Randall, which contained no adjustment for inflation,
                                21
amounted to “slightly more than one-twentieth of the limit on
contributions . . . before the Court in Buckley.” Id. at 250. That,
to the Court, constituted a “difference in kind” rather than just
“in degree.” Id. at 260.

     That is untrue of the $2,600 per-election contribution limit
we consider here. Plaintiffs do not contend otherwise. They
do not argue that the contribution ceiling is “too low” to permit
an effective campaign. Id. at 248. That is, they “do not
challenge the specific dollar amount Congress has chosen” for
the per-election limit. Plaintiffs’ Opening Br. 12.

     Plaintiffs instead accept FECA’s $2,600 contribution limit
as a given. They argue that Congress, having established a
$2,600 per-election ceiling, must allow a contributor to treat
that limit as if it were effectively a $5,200 per-cycle ceiling.
For all the reasons explained, we reject plaintiffs’ First
Amendment challenge to the statute’s per-election structure.

                                4.

     Plaintiffs do not suggest that Congress’s choice of a per-
election structure is otherwise arbitrary. Nor could they make
any such argument.

     A per-election ceiling promotes the ability of candidates to
gain adequate funding for each election in which they must
compete. States, in exercising their constitutional authority to
“prescribe the time, place, and manner of electing
Representatives and Senators,” Arizona v. Inter Tribal Council
of Ariz., Inc., 133 S. Ct. 2247, 2253 (2013), have adopted
varying structures. A state might allow for only a single round
of elections, it might adhere to the more conventional structure
of a primary election followed by a general election, or it might
also provide for runoff elections. See Holmes, 99 F. Supp. 3d
                               22
at 132-33. A per-election ceiling enables a candidate to raise
the same level of funds for each election, regardless of the
number of elections in which a given state’s regime might call
for her to participate. Otherwise, for instance, a candidate
might be left with insufficient funds with which to compete in
a runoff election.

     Relatedly, a per-election framework guards against unduly
advantaging candidates (often incumbents) who face little
meaningful opposition in a party primary. See Randall, 548
U.S. at 268 (Thomas, J., concurring in the judgment). In a per-
cycle system, an incumbent confronting no serious primary
opponent could more readily conserve contributions for use in
the general election, whereas an opponent who competed in a
contested primary presumably would have expended
considerable resources to survive that stage. A per-election
structure, by contrast, is naturally geared to enable candidates
to raise equivalent amounts for use in the primary and general
elections.

     A per-election structure also can be understood to
reinforce the First Amendment associational interests
embodied in campaign contributions to a candidate. The act of
associating with a candidate in a primary election, as compared
with a general election, might be seen to concern distinct
associational interests: the two elections serve a different
purpose, involve a different field of candidates, and frequently
feature a discussion of different issues and priorities.
Congress, for such reasons, could conclude that affiliating with
a candidate in the general election entails a different exercise
of associational interests than doing so in the primary election.
Contributing to one candidate in the primary election and to
another in the general election thus involves a different
associational tie than contributing to the same candidate in
both. That understanding coheres with a contribution ceiling
                               23
that operates separately with respect to each of those elections
rather than an overarching, per-cycle ceiling that indistinctly
envelops both.

     None of this is to say that Congress was obligated to select
a per-election structure for FECA’s base contribution limits.
The question before us is whether Congress could choose a per-
election format consistent with the First Amendment, not
whether it had to do so. Congress’s choice in that regard was
a constitutionally permissible one.

                              III.

    We finally consider certain regulations promulgated by the
Federal Election Commission and invoked by plaintiffs in
support of their constitutional challenge to the statute. While
those regulations permit commingling of primary-election and
general-election contributions in certain circumstances, they do
not undermine our conclusion that Congress could choose a
per-election structure consistent with the First Amendment.

     Plaintiffs point to two regulations. The first permits a
contributor to make a single payment of up to $5,200 during
the primary election, and then calls for the campaign to refund
any amounts above the $2,600 per-election cap or set aside the
excess funds for use in the general election (if the candidate
advances to that stage). 11 C.F.R. § 110.1(b)(5)(ii)(B).
Separately, the second regulation enables a campaign to
transfer any unused primary-election funds to the general
election. 11 C.F.R. § 110.3(c)(3). Those regulations, taken
together, permit an individual to contribute $5,200 at the time
of the primary election and then allow the campaign to transfer
any or all of the funds for use in the general election.
                               24
     Plaintiffs do not contest the constitutionality or lawfulness
of the regulations in this proceeding. They challenge only the
statute. And the theory of their challenge to the statute’s per-
election structure does not turn on the leeway afforded by the
regulations to transfer contributed funds from the primary to
the general election. Plaintiffs’ argument instead is that,
regardless of any such transfers, the First Amendment entitles
them to contribute $5,200 to a candidate in the general election
if they made no contribution to her in the primary.

     Plaintiffs invoke the regulations in questioning whether
the statute’s per-election ceiling serves any meaningful interest
given that, under the regulations, contributions in the primary
election may be transferred and spent by the campaign in the
general election. We are unpersuaded by plaintiffs’ reliance on
the regulations.

     The first regulation gives a person the convenience of
making contributions to a candidate for the primary and general
elections in a single, up front, $5,200 payment. The contributor
remains fully subject to FECA’s per-election ceiling of $2,600,
but can make an advance contribution for the general election
contemporaneously with any contribution for the primary
election. If the candidate fails to proceed to the general
election, the contributor is entitled to a refund of any donations
exceeding the $2,600 limit for the primary election. See 11
C.F.R. § 110.1(b)(5)(ii)(B)(5).        That regulation thus is
consistent with the statute’s $2,600 per-election contribution
ceiling for individuals.

    The second regulation, which permits campaigns to roll
over unused funds, does not speak to an individual’s
contributions to a campaign. It instead pertains to the
expenditure of contributed funds by the campaign, allowing the
campaign to transfer unused funds from the primary election to
                               25
pay expenses in the general election. 11 C.F.R. § 110.3(c)(3).
A contributor does not direct the transfer of primary-election
funds to the general election—any decision to do so is an
independent one on the part of the campaign.

     Insofar as a campaign’s latitude to transfer funds from one
election to the next could be perceived to impeach the integrity
of the statute’s per-election structure, that concern would arise
from the regulation, not the statute. And even assuming the
regulation could be viewed to have the effect in certain
circumstances of reshaping the statute’s per-election ceiling
into a form of a per-cycle limit, that would not afford a basis to
invalidate the statute under the First Amendment:                a
contribution ceiling needs to contain some timeframe, and both
a per-election and per-cycle structure, as we have seen, are
among the constitutionally permissible options.

                       *   *    *   *    *

     For the foregoing reasons, we reject plaintiffs’ challenge
to the per-election structure of FECA’s base contribution
ceilings for individuals.

                                                     So ordered.
