Syllabus

association, and to limit the association to those people, Democratic Party of United States v. Wisconsin ex rel. La Follette, 450 U. S. 107, 122. In no area is the political association's right to exclude more important than in its candidate-selection process. That process often determines the party's positions on significant public policy issues, and it is the nominee who is the party's ambassador charged with winning the general electorate over to its views. The First Amendment reserves a special place, and accords a special protection, for that process, Eu, supra, at 224, because the moment of choosing the party's nominee is the crucial juncture at which the appeal to common principles may be translated into concerted action, and hence to political power, Tashjian, supra, at 216. California's blanket primary violates these principles. Proposition 198 forces petitioners to adulterate their candidate-selection process-a political party's basic function-by opening it up to persons wholly unaffiliated with the party, who may have different views from the party. Such forced association has the likely outcome-indeed, it is Proposition 198's intended outcome-of changing the parties' message. Because there is no heavier burden on a political party's associational freedom, Proposition 198 is unconstitutional unless it is narrowly tailored to serve a compelling state interest. See Timmons v. Twin Cities Area New Party, 520 U. S. 351, 358. Pp. 572-582.

(b) None of respondents' seven proffered state interests-producing elected officials who better represent the electorate, expanding candidate debate beyond the scope of partisan concerns, ensuring that disenfranchised persons enjoy the right to an effective vote, promoting fairness, affording voters greater choice, increasing voter participation, and protecting privacy-is a compelling interest justifying California's intrusion into the parties' associational rights. Pp. 582-586. 169 F. 3d 646, reversed.

SCALIA, J., delivered the opinion of the Court, in which REHNQUIST, C. J., and O'CONNOR, KENNEDY, SOUTER, THOMAS, and BREYER, JJ., joined. KENNEDY, J., filed a concurring opinion, post, p. 586. STEVENS, J., filed a dissenting opinion, in which GINSBURG, J., joined as to Part I, post, p. 590.

George Waters argued the cause for petitioners. With him on the briefs were Lance H. Olson, N. Eugene Hill, and Charles H. Bell, Jr.

Thomas F. Gede, Special Assistant Attorney General of California, argued the cause for respondents. With him on the brief were Bill Lockyer, Attorney General, Manuel

Opinion of the Court

M. Medeiros, Senior Assistant Attorney General, Andrea Lynn Hoch, Lead Supervising Deputy Attorney General, and James P. Clark.*

JUSTICE SCALIA delivered the opinion of the Court.

This case presents the question whether the State of California may, consistent with the First Amendment to the United States Constitution, use a so-called “blanket” primary to determine a political party's nominee for the general election.

I

Under California law, a candidate for public office has two routes to gain access to the general ballot for most state and federal elective offices. He may receive the nomination of a qualified political party by winning its primary,1 see Cal.

*Briefs of amici curiae urging reversal were filed for the Eagle Forum Education & Legal Defense Fund et al. by Erik S. Jaffe; for the Republican National Committee et al. by Joseph E. Sandler and Thomas J. Josefiak; and for the Republican Party of Alaska, Inc., et al. by Kenneth P. Jacobus.

Briefs of amici curiae urging affirmance were filed for the State of Washington et al. by Christine O. Gregoire, Attorney General of Washington, Maureen A. Hart, Senior Assistant Attorney General, Jeffrey T. Evan, Assistant Attorney General, Bruce Botelho, Attorney General of Alaska, and Dan Schweitzer; for California Governor Gray Davis by Demetrios A. Boutris, D. Robert Shuman, Shelleyanne W. L. Chang, and Allen Sumner; for Alaskan Voters for an Open Primary (AVOP) by Max F. Gruenberg, Jr., and for Senator William E. Brock et al. by James M. Johnson.

Briefs of amici curiae were filed for the Brennan Center for Justice by Burt Neuborne; and for the Northern California Committee for Party Renewal et al. by E. Mark Braden.

1A party is qualified if it meets one of three conditions: (1) in the last gubernatorial election, one of its statewide candidates polled at least two percent of the statewide vote; (2) the party's membership is at least one percent of the statewide vote at the last preceding gubernatorial election; or (3) voters numbering at least 10 percent of the statewide vote at the last gubernatorial election sign a petition stating that they intend to form a new party. See Cal. Elec. Code Ann. § 5100 (West 1996 and Supp. 2000).

Opinion of the Court

Elec. Code Ann. §§ 15451, 13105(a) (West 1996); or he may file as an independent by obtaining (for a statewide race) the signatures of one percent of the State's electorate or (for other races) the signatures of three percent of the voting population of the area represented by the office in contest, see §8400.

Until 1996, to determine the nominees of qualified parties California held what is known as a "closed" partisan primary, in which only persons who are members of the political party-i. e., who have declared affiliation with that party when they register to vote, see Cal. Elec. Code Ann. §§ 2150, 2151 (West 1996 and Supp. 2000)—can vote on its nominee, see Cal. Elec. Code Ann. §2151 (West 1996). In 1996 the citizens of California adopted by initiative Proposition 198. Promoted largely as a measure that would "weaken" party "hard-liners" and ease the way for "moderate problemsolvers," App. 89-90 (reproducing ballot pamphlet distributed to voters), Proposition 198 changed California's partisan primary from a closed primary to a blanket primary. Under the new system, "[a]ll persons entitled to vote, including those not affiliated with any political party, shall have the right to vote . . . for any candidate regardless of the candidate's political affiliation." Cal. Elec. Code Ann. § 2001 (West Supp. 2000); see also §2151. Whereas under the closed primary each voter received a ballot limited to candidates of his own party, as a result of Proposition 198 each voter's primary ballot now lists every candidate regardless of party affiliation and allows the voter to choose freely among them. It remains the case, however, that the candidate of each party who wins the greatest number of votes “is the nominee of that party at the ensuing general election." Cal. Elec. Code Ann. § 15451 (West 1996).2

2 California's new blanket primary system does not apply directly to the apportionment of Presidential delegates. See Cal. Elec. Code Ann. §§ 15151, 15375, 15500 (West Supp. 2000). Instead, the State tabulates the Presidential primary in two ways: according to the number of votes

Opinion of the Court

Petitioners in this case are four political parties—the California Democratic Party, the California Republican Party, the Libertarian Party of California, and the Peace and Freedom Party-each of which has a rule prohibiting persons not members of the party from voting in the party's primary.3 Petitioners brought suit in the United States District Court for the Eastern District of California against respondent California Secretary of State, alleging, inter alia, that California's blanket primary violated their First Amendment rights of association, and seeking declaratory and injunctive relief. The group Californians for an Open Primary, also respondent, intervened as a party defendant. The District Court recognized that the new law would inject into each party's primary substantial numbers of voters unaffiliated with the party. 984 F. Supp. 1288, 1298-1299 (1997). It further recognized that this might result in selection of a nominee different from the one party members would select, or at the least cause the same nominee to commit himself to different positions. Id., at 1299. Nevertheless, the District Court held that the burden on petitioners' rights of association was not a severe one, and was justified by state interests ultimately reducing to this: "enhanc[ing] the democratic nature of the election process and the representativeness of elected officials." Id., at 1301. The Ninth Circuit, adopting the District Court's opinion as its own, affirmed. 169 F. 3d 646 (1999). We granted certiorari. 528 U. S. 1133 (2000).

each candidate received from the entire voter pool and according to the amount each received from members of his own party. The national parties may then use the latter figure to apportion delegates. Nor does it apply to the election of political party central or district committee members; only party members may vote in these elections. See Cal. Elec. Code Ann. §2151 (West 1996 and Supp. 2000).

3 Each of the four parties was qualified under California law when they filed this suit. Since that time, the Peace and Freedom Party has apparently lost its qualified status. See Brief for Petitioners 16 (citing Child of the '60s Slips, Los Angeles Times, Feb. 17, 1999, p. B-6).

Respondents rest their defense of the blanket primary upon the proposition that primaries play an integral role in citizens' selection of public officials. As a consequence, they contend, primaries are public rather than private proceedings, and the States may and must play a role in ensuring that they serve the public interest. Proposition 198, respondents conclude, is simply a rather pedestrian example of a State's regulating its system of elections.

We have recognized, of course, that States have a major role to play in structuring and monitoring the election process, including primaries. See Burdick v. Takushi, 504 U. S. 428, 433 (1992); Tashjian v. Republican Party of Conn., 479 U. S. 208, 217 (1986). We have considered it "too plain for argument," for example, that a State may require parties to use the primary format for selecting their nominees, in order to assure that intraparty competition is resolved in a democratic fashion. American Party of Tex. v. White, 415 U. S. 767, 781 (1974); see also Tashjian, supra, at 237 (SCALIA, J., dissenting). Similarly, in order to avoid burdening the general election ballot with frivolous candidacies, a State may require parties to demonstrate "a significant modicum of support" before allowing their candidates a place on that ballot. See Jenness v. Fortson, 403 U. S. 431, 442 (1971). Finally, in order to prevent "party raiding"-a process in which dedicated members of one party formally switch to another party to alter the outcome of that party's primary-a State may require party registration a reasonable period of time before a primary election. See Rosario v. Rockefeller, 410 U. S. 752 (1973). Cf. Kusper v. Pontikes, 414 U. S. 51 (1973) (23-month waiting period unreasonable). What we have not held, however, is that the processes by which political parties select their nominees are, as respondents would have it, wholly public affairs that States