Mr. Justice Stewart
delivered the opinion of the Court.
Under § 7-43 (d) of the Illinois Election Code, a person is prohibited from voting in the primary election of a political party if he has voted in the primary of any other party within the preceding 23 months. Appellee, Harriet G. Pontikes, is a qualified Chicago voter who voted in a Republican primary in February 1971; she wanted to vote in a March 1972 Democratic primary, but was barred from doing so by this 23-month rule. She filed a complaint for declaratory and in-junctive relief in the United States District Court for the Northern District of Illinois, alleging that § 7-43 (d) unconstitutionally abridged her freedom to associate with the political party of her choice by depriving her of the opportunity to vote in the Democratic primary. A statutory three-judge court was convened, and held, one judge dissenting, that the 23-month rule is unconstitutional. 345 F. Supp. 1104. We noted probable jurisdiction of this appeal from that judgment. 411 U. S. 915.
I
At the outset, we are met by the appellants’ argument that the District Court should have abstained from adjudicating the constitutionality of the 23-month rule. They base this argument upon that portion of § 7-43 (d) which provides that:
“ [Participation by a primary elector in a primary of a political party which, under the provisions of Section 7-2 of this Article, is a political party within a city, village or incorporated town or town only and entitled hereunder to make nominations of candidates for city, village or incorporated town or town offices only, and for no other office or offices, shall not disqualify such primary elector from participating in other primaries of his party . . . Ill. Rev. Stat., c. 46, § 7-43 (d).
The appellants note that the February 1971 Republican primary election in which Mrs. Pontikes voted involved only nominations for the offices of mayor, city clerk, and city treasurer of the city of Chicago. They claim that the state courts might interpret this 1971 primary to have been one of a “political party within a city . . . only,” and thus outside the purview of the 23-month rule.
As we stated in Lake Carriers’ Assn. v. MacMullan, 406 U. S. 498, 509:
“Abstention is a ‘judge-made doctrine . . . , first fashioned in 1941 in Railroad Commission v. Pullman Co., 312 U. S. 496, [that] sanctions . . . escape [from immediate decision] only in narrowly limited “special circumstances,” Propper v. Clark, 337 U. S. 472, 492,' Zwickler v. Koota, 389 U. S. 241, 248 (1967), justifying ‘the delay and expense to which application of the abstention doctrine inevitably gives rise.' England v. Medical Examiners, 375 U. S. 411, 418 (1964).”
The paradigm of the “special circumstances” that make abstention appropriate is a case where the challenged state statute is susceptible of a construction by the state judiciary that would avoid or modify the necessity of reaching a federal constitutional question. Zwickler v. Koota, 389 U. S. 241, 249; Harrison v. NAACP, 360 U. S. 167, 176-177. Abstention in such circumstances not only serves to minimize federal-state friction, but also avoids premature and perhaps unnecessary constitutional adjudication. Harman v. Forssenius, 380 U. S. 528, 534. But the doctrine of abstention “contemplates that deference to state court adjudication only be made where the issue of state law is uncertain.” Ibid. Where, on the other hand, it cannot be fairly concluded that the underlying state statute is susceptible of an interpretation that might avoid the necessity for constitutional adjudication, abstention would amount to shirking the solemn responsibility of the federal courts to “guard, enforce, and protect every right granted or secured by the Constitution of the United States,” Robb v. Connolly, 111 U. S. 624, 637.
We think that the Illinois statute involved in this case is not fairly susceptible of a reading that would avoid the necessity of constitutional adjudication. The appellants’ argument — that the February 1971 Chicago Republican primary might be considered that of a “political party within a city . . . only” — is foreclosed by the decision of the Illinois Supreme Court in Faherty v. Board of Election Comm’rs, 5 Ill. 2d 519, 126 N. E. 2d 235. That decision made it clear that the kind of “local” primaries that are outside the scope of § 7-43 (d) are simply those of “ 'purely city . . . political part[ies]’ ”— those parties entitled, under § 7-2 of the Illinois Election Code, to make nominations for city offices only. Id., at 524, 126 N. E. 2d, at 238.
Since both the Democratic and Republican parties are, of course, entitled in Illinois to make nominations not only for city offices, but for congressional, state, and county offices as well, the Faherty court held that they were not within the statutory definition of “city” parties. It follows then, that despite the fact that the February 1971 Republican primary in which the appellee voted involved only nominations for offices within the city of Chicago, Mrs. Pontikes was still clearly barred by the 23-month rule from voting in the March 1972 Democratic primary. The District Court was thus wholly justified in declining to abstain from deciding the constitutional validity of the 23-month rule, and it is to that issue that we now turn.
II
There can no longer be any doubt that freedom to associate with others for the common advancement of political beliefs and ideas is a form of “orderly group activity” protected by the First and Fourteenth Amendments. NAACP v. Button, 371 U. S. 415, 430; Bates v. Little Rock, 361 U. S. 516, 522-523; NAACP v. Alabama, 357 U. S. 449, 460-461. The right to associate with the political party of one’s choice is an integral part of this basic constitutional freedom. Williams v. Rhodes, 393 U. S. 23, 30. Cf. United States v. Robel, 389 U. S. 258.
To be sure, administration of the electoral process is a matter that the Constitution largely entrusts to the States. But, in exercising their powers of supervision over elections and in setting qualifications for voters, the States may not infringe upon basic constitutional protections. See, e. g., Dunn v. Blumstein, 405 U. S. 330; Kramer v. Union School District, 395 U. S. 621; Carrington v. Rash, 380 U. S. 89. As the Court made clear in Williams v. Rhodes, supra, unduly restrictive state election laws may so impinge upon freedom of association as to run afoul of the First and Fourteenth Amendments. 393 U. S., at 30. And see id., at 35—41 (Douglas, J., concurring); id., at 41-48 (Harlan, J., concurring).
There can be little doubt that § 7-43 (d) substantially restricts an Illinois voter’s freedom to change his political party affiliation. One who wishes to change his party registration must wait almost two years before his choice will be given effect. Moreover, he is forced to forgo participation in any primary elections occurring within the statutory 23-month hiatus. The effect of the Illinois statute is thus to “lock” the voter into his pre-existing party affiliation for a substantial period of time following participation in any primary election, and each succeeding primary vote extends this period of confinement.
The 23-month rule does not, of course, deprive those in the appellee’s position of all opportunities to associate with the political party of their choice. But neither did the state attempts to compel disclosure of NAACP membership lists in Bates v. Little Rock and NAACP v. Alabama work a total restriction upon the freedom of the organization’s members to associate with each other. Rather, the Court found in those cases that the statutes under attack constituted a “substantial restraint” and a “significant interference” with the exercise of the constitutionally protected right of free association.
The same is true of §7-43(d). While the Illinois statute did not absolutely preclude Mrs. Pontikes from associating with the Democratic party, it did absolutely preclude her from voting in that party’s 1972 primary election. Under our political system, a basic function of a political party is to select the candidates for public office to be offered to the voters at general elections. A prime objective of most voters in associating themselves with a particular party must surely be to gain a voice in that selection process. By preventing the appellee-from participating at all in Democratic primary elections during the statutory period, the Illinois statute deprived her of any voice in choosing the party’s candidates, and thus substantially abridged her ability to associate effectively with the party of her choice.
HH f-H J — H
As our past decisions have made clear, a significant encroachment upon associational freedom cannot be justified upon a mere showing of a legitimate state interest. Bates v. Little Rock, supra, at 524; NAACP v. Alabama, supra, at 463. For even when pursuing a legitimate interest, a State may not choose means that unnecessarily restrict constitutionally protected liberty. Dunn v. Blumstein, 405 U. S., at 343. “Precision of regulation must be the touchstone in an area so closely touching our most precious freedoms.” NAACP v. Button, 371 U. S., at 438. If the State has open to it a less drastic way of satisfying its legitimate interests, it may not choose a legislative scheme' that broadly stifles the exercise of fundamental personal liberties. Shelton v. Tucker, 364 U. S. 479, 488.
The appellants here urge that the 23-month rule serves, the purpose of preventing “raiding” — the practice whereby voters in sympathy with one party vote in another’s primary in order to distort that primary’s results. It is said that our decision in Rosario v. Rockefeller, 410 U. S. 752, recognized the state interest in inhibiting “raiding,” and upheld the constitutional validity of legislation restricting a voter’s freedom to change parties, enacted as a means of serving that interest.
It is true, of course, that the Court found no constitutional infirmity in the New York delayed-enrollment statute under review in Rosario. That law required a voter to enroll in the party of his choice at least 30 days before a general election in order to be eligible to vote in the next party primary, and thus prevented a change in party affiliation during the approximately 11 months between the deadline and the primary election. It is also true that the Court recognized in Rosario that a State may have a legitimate interest in seeking to curtail “raiding,” since that practice may affect the integrity of the electoral process. Id., at 761. But it does not follow from Rosario that the Illinois statutory procedures also pass muster under the Fourteenth Amendment, for the Illinois Election Code differs from the New York delayed-enrollment law in a number of important respects.
The New York statute at issue in Rosario did not prevent voters from participating in the party primary of their choice; it merely imposed a time limit on enrollment. Under the New York law, a person who wanted to vote in a different party primary every year was not precluded from doing so; he had only to meet the requirement of declaring his party allegiance 30 days before the preceding general election. The New York law did not have the consequence of “locking” a voter into an unwanted party affiliation from one election to the next; any such confinement was merely the result of the elector's voluntary failure to take timely measures to enroll. Id., at 757-759. The Court therefore concluded that the New York delayed-enrollment law did not prevent voters “from associating with the political party of their choice.” Id., at 762. And see id., at 758 and n. 8.
The basic difference in the Illinois law is obvious. Since the appellee here voted in the 1971 Republican primary, the state law absolutely precluded her from participating in the 1972 Democratic primary. Unlike the petitioners in Rosario, whose disenfranchisement was caused by their own failure to take timely measures to enroll, there was no action that Mrs. Pontikes could have taken to make herself eligible to vote in the 1972 Democratic primary. The Illinois law, unlike that of New York, thus “locks” voters into a pre-existing party affiliation from one primary to the next, and the only way to break the “lock” is to forgo voting in any primary for a period of almost two years.
In other words, while the Court held in Rosario that the New York delayed-enrollment scheme did not. prevent voters from exercising their constitutional freedom to associate with the political party of their choice, the Illinois 23-month rule clearly does just that. It follows that the legitimate interest of Illinois in preventing “raiding” cannot justify the device it has chosen to effect its goal. For that device conspicuously infringes upon basic constitutional liberty. Far from supporting the validity of the Illinois legislation, the Court’s decision in Rosario suggests that the asserted state interest can be attained by “less drastic means,” which do not unnecessarily burden the exercise of constitutionally protected activity.
We conclude, therefore, that § 7-43 (d) of the Illinois Election Code unconstitutionally infringes upon the right of free political association protected by the First and Fourteenth Amendments. The judgment of the District Court is accordingly
Affirmed.
The Chief Justice concurs in the result.
Ill. Rev. Stat., c. 46, § 7-43 provides, in pertinent part:
“No person shall be entitled to vote at a primary:
“(d) If he has voted at a primary held under this Article 7 of another political party within a period of 23 calendar months next preceding the calendar month in which such primary is held: Provided, participation by a primary elector in a primary of a political party which, under the provisions of Section 7-2 of this Article, is a political party within a city, village or incorporated town or town only and entitled hereunder to make nominations of candidates for city, village or incorporated town or town offices only, and for no other office or offices, shall not disqualify such primary elector from participating in other primaries of his party: And, provided, that no qualified voter shall be precluded from participating in the primary of any purely city, village or incorporated town or town political party under the provisions of Section 7-2 of this Article by reason of such voter having voted at the primary of another political party within a period of 23 calendar months next preceding the calendar month in which he seeks to participate is held.”
The Republican primary in which the appellee voted involved nominations for the offices of mayor, city clerk, and city treasurer of Chicago.
The March 1972 Democratic primary involved, inter alia, nominations for Governor, United States Senator, United States Representative, state legislators, county officers, and delegates to the National Convention of the Democratic Party.
28 U. S. C. §§2281, 2284.
The District Court upheld the constitutional validity of Ill. Rev. Stat., c. 46, §§ 7-43 (a) and 7-44, which require a declaration of party affiliation as a prerequisite to voting in a primary election. This holding, which was unanimous, has not been appealed.
This case was consolidated in the District Court with a similar action brought by two other voters against the county clerk of Lake County, Illinois. The defendant in that case has not appealed from the District Court’s judgment.
The appellants in this case are members of the Chicago Board of Election Commissioners, who are responsible for administering the provisions of the Illinois Election Code within the city. See Ill. Rev. Stat., c. 46, § 6-21 et seq.
Bracketed material in original.
Ill. Rev. Stat., c. 46, § 7-2 defines the term “political party” under Illinois law, and states the offices for which various types of political parties are entitled to make nominations. Under § 7-2, a party that garners more than 5% of the entire vote cast at a statewide general election is defined as a “political party within the State,” and is entitled to make nominations for all state and county offices in the next succeeding primary. Similarly, a party that polls more than 5% of the entire vote cast at a municipal general election is defined as a “political party within . . . [a] city,” and is entitled to make nominations for city elective positions at the next succeeding primary.
Under § 7-43 (d), a “political party within a city . . . only” is one that has qualified under §7-2 to make only city nominations; in other words, a party that has polled more than 5% of the vote at the preceding municipal general election, but less than 5% of the vote at the preceding statewide general election. Obviously, the Republican party, in whose 1971 Chicago primary the appellee voted, does not fit within this description.
It is true, as the appellants argue, that the plaintiff in Faherty v. Board of Election Comm’rs, 5 Ill. 2d 519, 126 N. E. 2d 235, wished to vote in a Chicago Democratic primary after having voted, within the past year, in a statewide Republican primary; thus, the factual setting in Faherty was precisely the converse of that here. This, however, is a distinction without a difference. The holding of Faherty was that Republican and Democratic primaries, even those involving only citywide offices, were not primaries of political parties “within a city . . . only.” See n. 9, supra. Thus, these primaries are fully within the purview of the § 7-43 (d) 23-month rule.
See Art. I, §2; Art. II, §1. With respect to elections to federal office, however, the Court has held that Congress has power to establish voter qualifications. Oregon v. Mitchell, 400 U. S. 112.
NAACP v. Alabama, 357 U. S. 449, 462.
Bates v. Little Rock, 361 U. S. 516, 523.
N. Y. Election Law § 186.
New York presidential primaries are held in June; thus, in presidential election years, the cutoff date prescribed by § 186 occurs about eight months before the primary. Rosario v. Rockefeller, 410 U. S. 752, 760.
She could, of course, have made herself eligible to vote in the 1972 Democratic primary by forgoing participation in the 1971 Republican primary. But such a course would have prevented her from associating with the party of her choice in 1971, and thus in no way would have obviated the constitutional deficiencies inherent in the Illinois law.