Mr. Justice White
delivered the opinion of the Court.
These cases began when appellants, minority political parties and their candidates, qualified voters supporting the minority party candidates, and independent unaffiliated candidates, brought four separate actions in the United States District Court for the Western District of Texas against the Texas Secretary of State seeking declaratory and injunctive relief against the enforcement of various sections of the Texas Election Code.
The American Party of Texas sought ballot position at the general election in 1972 for a slate of candidates for various statewide and local officers, including governor and county commissioner.1 The New Party of Texas wanted ballot recognition for its candidates for the general election for governor, Congress, state representative and county sheriff. The Socialist Workers Party made similar claims with respect to its candidates for governor, lieutenant governor and United States Senator.2 Laurel Dunn, a nonpartisan candidate, at[771]*771tempted to run for the United States House of Representatives from the Eleventh Congressional District. In his action, he represented himself and other named independent candidates for state and local offices. Finally, Robert Hainsworth sought election as state representative from District No. 86.
In these actions, it was alleged that, by excluding appellants from the general election ballot, various provisions of the Texas Election Code infringed their First and Fourteenth Amendment right to associate for the advancement of political beliefs and invidiously discriminated against new and minority political parties, as well as independent candidates. Appellants sought to enjoin the enforcement of the challenged provisions in the forthcoming November 1972 general election. They also challenged the failure of the Texas law to require printing minority party and independent candidates on absentee ballots and the exclusion of minority parties from the benefits of the McKool-Stroud Primary Law of 1972. The individual cases involving the parties in No. 72-887 were consolidated, and a statutory three-judge District Court was convened. Following a trial, the District Court denied all relief after holding that, in their totality, the challenged provisions served a compelling state interest and did not suffocate the election process. Raza Unida Party v. Bullock, 349 F. Supp. 1272 (WD Tex. 1972). Hainsworth, appellant in No. 72-942, was [772]*772also subsequently denied relief on similar grounds. Two separate appeals were taken, and we noted probable jurisdiction. 410 U. S. 965. We affirm the judgment of the District Court in No. 72-942, and in No. 72-887, except as the latter relates to the Socialist Workers Party and Texas’ absentee ballot provisions.
I
The State of Texas has established a detailed statutory scheme for regulating the conduct of political parties as it relates to qualifying for participation in the electoral process. Under the laws challenged in this case, four methods are provided for nominating candidates to the ballot for the general election.3
Candidates of political parties whose gubernatorial candidate polled more than 200,000 votes in the last general election may be nominated by primary election only, and the nominees of these parties automatically appear on the ballot. Tex. Election Code, Art. 13.02 (1967).4 Texas holds a statewide primary for these [773]*773major parties on the first Saturday in May, with a runoff primary the first Saturday in June, should no candidate garner a majority. Art. 13.03 (1967).
[774]*774Because their candidates polled less than 2% of the total gubernatorial vote in the preceding general election or they did not nominate a candidate for governor, the political parties in this litigation were required to pursue the third method for ballot qualification: precinct nominating conventions and if the required support was not evidenced at the conventions, the circulation of petitions for signatures. Art. 13.45 (2) (Supp. 1973).6
[773]*773Candidates of parties whose candidate polled less than 200,000 votes, but more than 2% of the total vote cast for governor in the last general election may be nominated and thereby qualify for the general election ballot by primary election or nominating conventions. Art. 13.45 (1) (Supp. 1973).5 The nominating conventions [774]*774are held sequentially, with the precinct conventions on the same date as the statewide primaries for the major parties (the first Saturday in May), the county conventions on the following Saturday, and the state convention on the second Saturday in June. Art. 13.47 (Supp. 1974); Art. 13.48 (1967).
[775]*775Finally, unaffiliated nonpartisan or independent candidates such as Dunn and Hainsworth could qualify by filing within a fixed period a written application or petition signed by a specified percentage of the vote cast for governor in the relevant electoral district in the last general election. Arts. 13.50, 13.51 (1967).7
[776]*776II
We consider first the appeals of the political parties and their supporters. Article 13.45 (2) (Supp. 1973) of the Texas Election Code, the validity of which is at issue [777]*777here, requires that the political parties to which it applies nominate candidates through the process of precinct, county, and state conventions. The party must also evidence support by persons numbering at least 1 % of the total vote cast for governor at the last preceding general election. In 1972, this number was approximately 22,000 electors. Two opportunities are offered to satisfy the 1% signature requirement. At the statutorily mandated [778]*778precinct nominating conventions, held on the first Saturday in May and the same day as the major party primary, the party must prepare a list of all participants, who must be qualified voters, along with other pertinent information. The list is to be forwarded to the Secretary of State within 20 days after the convention. If it reveals the necessary support and if the party has satisfied the other statutory requirements imposed upon all political parties, the Secretary of State will certify that the party is entitled to be placed on the general election ballot.
Should the party not obtain the requisite 1% convention participation, supplemental petitions may be circulated for signature. When these are signed by a sufficient number of qualified voters in addition to the convention lists to make a combined total of the requisite 1%, the party qualifies for the ballot. Approximately 55 days after the general primary election in May are allotted for the supplementation process. A voter who has already participated in any other party's primary election or nominating process is ineligible to sign the petition. Furthermore, each signatory must be administered and sign an oath that he is a qualified voter and has not participated in any other party’s nominating or qualification proceedings. The oath must also be notarized.
The American Party of Texas was able to secure only 2,732 signatures at its precinct conventions in May 1972. By the deadline for filing the precinct lists and supplemental petitions, the total had risen to 7,828, far short of the over 22,000 required signatures. Brief for American Party of Texas 2-3.8 The Texas New Party ap[779]*779parently made no effort to comply with the 1% requirement.9 Two relatively small parties, however, which were also plaintiffs in this litigation, La Raza Unida Party and the Socialist Workers Party, complied with the qualification provisions of Art. 13.45 (2) (Supp. 1973) and were placed on the general election ballot.
The party appellants challenge various aspects of the Texas ballot qualification system as they interact with each other: the 1 % support requirement with its precinct conventions and petition apparatus, the preprimary ban on petition circulation, the disqualification from signing of those voters participating in another party’s nominating process, the 55-day limitation on securing signatures, and the notarization requirement.10 They assert that [780]*780these preconditions for access to the general election ballot are impermissible burdens on rights secured by the First and Fourteenth Amendments and violate the Equal Protection Clause of the Fourteenth Amendment as invidious discriminations against new or small political parties.
We have concluded that these claims are without merit. We agree with the District Court that whether the qualifications for ballot position are viewed as substantial burdens on the right to associate or as discrimi-nations against parties not polling 2% of the last election vote, their validity depends upon whether they are necessary to further compelling state interests, Storer v. Brown, ante, at 729-733.11 But we also agree with the District [781]*781Court that the foregoing limitations, whether considered alone or in combination, are constitutionally valid measures, reasonably taken in pursuit of vital state objectives that cannot be served equally well in significantly less burdensome ways.
It is too plain for argument, and it is not contested here, that the State may limit each political party to one candidate for each office on the ballot and may insist that intraparty competition be settled before the general election by primary election or by party convention. See Storer v. Brown, ante, at 733-736. Neither can we take seriously the suggestion made here that the State has invidiously discriminated against the smaller parties by insisting that their nominations be by convention, rather than by primary election. We have considered the arguments presented, but we are wholly unpersuaded by the record before us that the convention process is invidiously more' burdensome than the primary election, followed by a runoff election where necessary, particularly where the major party, in addition to the elections, must also hold its precinct, county, and state conventions to adopt and promulgate party platforms and to conduct other business.12 If claiming an equal protection violation, the appellants’ burden was to demonstrate in the first instance a discrimination against them of some substance. “Statutes create many classifications which do not deny equal protection; it is only 'invidious discrimination’ which offends the Constitution.” Ferguson v. Skrupa, 372 U. S. 726, 732 (1963) (footnote omitted). Appellants’ burden is not satisfied by mere assertions that small parties must proceed by convention when major parties are permitted to choose their candidates by primary election. The procedures are different, but [782]*782the Equal Protection Clause does not necessarily forbid the one in preference to the other.13
To obtain ballot position, the parties subject to Art. 13.45 (2) (Supp. 1973), as were these appellants, were also required to demonstrate support from electors equal in number to 1 % of the vote for governor at the last general election. Appellants apparently question whether they must file any list of supporters where the major parties are required to file none. But we think that the State’s admittedly vital interests14 are sufficiently implicated to insist that political parties appearing on the general ballot demonstrate a significant, measurable quantum of commnuity support. So long as the larger parties must demonstrate major support among the electorate at [783]*783the last election, whereas the smaller parties need not, the latter, without being invidiously treated, may be required to establish their position in some other manner. Of course, what is demanded may not be so excessive or impractical as to be in reality a mere device to always, or almost always, exclude parties with significant support from the ballot. The Constitution requires that access to the electorate be real, not “merely theoretical.” Jenness v. Fortson, 403 U. S. 431, 439 (1971).
The District Court recognized that any fixed percentage requirement is necessarily arbitrary, but we agree with it that the required measure of support — 1% of the vote for governor at the last general election and in this instance 22,000 signatures — falls within the outer boundaries of support the State may require before according political parties ballot position.15 To demonstrate this degree of support does not appear either impossible or impractical, and we are unwilling to assume that the requirement imposes a substantially greater hardship on minority party access to the ballot.16 Two political par[784]*784ties which were plaintiffs in this very litigation qualified for the ballot under Art. 13.45 (2) (Supp. 1973) in the 1972 election. It is not, therefore, immediately obvious that the Article, on its face or as it operates in practice, imposes insurmountable obstacles to fledgling political party efforts to generate support among the electorate and to evidence that support within the time allowed.
The aspiring party is free to campaign before the primary and to compete with the major parties for voter support on primary election and precinct convention day. Any voter, however registered, may attend the new party’s precinct convention and be counted toward the necessary 1% level. Unlike the independent candidate under Texas law, see infra, at 788, and his California counterpart, see Storer v. Brown, ante, at 738, a party qualifying under Art. 13.45 (2) (Supp. 1973) need not wait until the primary to crystallize its support among the voters. It is entitled to compete before the primary election and to count noses at its convention on primary day, just as the major parties and their candidates count their primary votes. Furthermore, should they fall short of the magic figure, they have another chance — they may make up the shortage and win ballot position by circulating petitions for signature for a period of 55 days beginning after the primary and ending 120 days prior to the general election.
[785]*785It is true that at this juncture the pool of possible supporters is severely reduced, for anyone voting in the just-completed primary is no longer qualified to sign the petition requesting that the petitioning party and its nominees for public office be listed on the ballot. Appellants attack this restriction, but, as such, it is nothing more than a prohibition against any elector’s casting more than one vote in the process of nominating candidates for a particular office. Electors may vote in only one party primary; and it is not apparent to us why the new or smaller party seeking voter support should be entitled to get signatures of those who have already voted in another nominating primary and have already demonstrated their preference for other candidates for the same office the petitioning party seeks to fill. We think the three-judge District Court in Jackson v. Ogilvie, 325 F. Supp. 864, 867 (ND Ill.), aff’d, 403 U. S. 925 (1971), aptly characterized the situation in upholding a state election law provision preventing a voter from both voting in the primary and signing an independent election petition:
“Thus, the state’s scheme attempts to ensure that each qualified elector may in fact exercise the political franchise. He may exercise it either by vote or by signing a nominating petition. He cannot have it both ways.” 17
[786]*786We have previously held that to protect the integrity of party primary elections, States may establish waiting periods before voters themselves may be permitted to change their registration and participate in another party’s primary. Rosario v. Rockefeller, 410 U. S. 752 (1973). Cf. Kusper v. Pontikes, 414 U. S. 51 (1973). Likewise, it seems to us that the State may determine that it is essential to the integrity of the nominating process to confine voters to supporting one party and its candidates in the course of the same nominating process. At least where, as here, the political parties had access to the entire electorate and an opportunity to commit voters on primary day, we see nothing invidious in disqualifying those who have voted at a party primary from signing petitions for another party seeking ballot position for its candidates for the same offices.
Neither do we consider that the 55 days is an unduly short time for circulating supplemental petitions. Given that time span, signatures would have to be obtained only at the rate of 400 per day to secure the entire 22,000, or four signatures per day for each 100 canvassers— only two each per day if half the 22,000 were obtained at the precinct conventions on primary day. A petition procedure may not always be a completely precise or satisfactory barometer of actual community support for a political party, but the Constitution has never required [787]*787the States to do the impossible. Dunn v. Blumstein, 405 U. S. 330, 360 (1972). Hard work and sacrifice by-dedicated volunteers are the lifeblood of any political organization. Constitutional adjudication and common sense are not at war with each other, and we are thus unimpressed with arguments that burdens like those imposed by Texas are too onerous, especially where two of the original party plaintiffs themselves satisfied these requirements.18
Finally, there remains another facet to the signature requirement. Article 13.45 (2) (Supp. 1973) provides that all signatures evidencing support for the party, whether originating at the precinct conventions or with supplemental petitions circulated after primary day, must be notarized. The parties object to this requirement, but make little or no effort to demonstrate its impracticability or that it is unusually burdensome. The District Court determined that it was not, indicating that one of the plaintiff political parties had conceded as much. The District Court also found no alternative if the State was to be able to enforce its laws to prevent voters from crossing over or from voting twice for the same office. On the record before us, we are in no position to disagree.
In sum, Texas “in no way freezes the status quo, but implicitly recognizes the potential fluidity of American political life.” Jenness v. Fortson, 403 U. S., at 439. It [788]*788affords minority political parties a real and essentially equal opportunity for ballot qualification. Neither the First and Fourteenth Amendments nor the Equal Protection Clause of the Fourteenth Amendment requires any more.
Ill
Appellants Dunn and Hainsworth challenged Arts. 13.50 and 13.51, which govern the eligibility of nonpartisan or independent candidates for general election ballot position. Regardless of the office sought, an independent candidate must file, within 30 days after the second or runoff primary election, a written petition signed by a specified number of qualified voters. The signatures required vary with the office sought. Dunn was required to obtain signatures equaling 3% of the 1970 vote for governor in the congressional district in which he desired to run; Hainsworth, a candidate for the State House of Representatives, needed 5% of the same vote in his locality. Article 13.50, however, states that in no event would candidates for any “district office,” as Dunn and Hainsworth were,19 be required to file more that 500 signatures. The law also provides that a voter may not sign more than one petition for the same office and is barred from signing any petitions if he voted at either primary election of any party at which a nomination was made for that office. Each voter signing an independent candidate’s petition must also subscribe to a notarized oath declaring his nonparticipation in any political party’s nominating process. Art. 13.51.
Dunn and Hainsworth contend that the First and Fourteenth Amendments, including the Equal Protection Clause, forbid the State to impose unduly burdensome conditions on their opportunity to appear on the general election ballot. The principle is unexception[789]*789able, cf. Storer v. Brown, ante, at 738, 739, 740, 746; but requiring independent candidates to evidence a “significant modicum of support” 20 is not unconstitutional. Demanding signatures equal in number to 3% or 5%- of the vote in the last election is not invalid on its face, see Jenness v. Fortson, supra, and with a 500-signature limit in any event, the argument that the statute is unduly burdensome approaches the frivolous.
It is true that those who have voted in the party primaries are ineligible to sign an independent candidate’s petition. In theory at least, the consequence of this restriction is that the pool of eligible signers of an independent candidate’s petition, calculated by subtracting from all eligible voters in the 1972 primaries all those who voted in the primary and then adding new registrations since the closing of the registration books, could be reduced nearly to zero or to so few qualified electors that securing even 500 of them would be an impractical undertaking. But this likelihood seems remote, to say the least, particularly when it will be very likely that a substantial percentage, perhaps 25%, of the total registered voters will not turn out for the primary and will thus be eligible to sign petitions,21 along with all new registrants [790]*790since the closing of the registration books prior to the primary. In any event, nothing in the record before us indicates what the total vote in the last election was in the districts at issue here, nothing showing what the primary vote would be or was in 1972, and nothing suggesting what the size of the pool of eligible signers might be. As the District Court noted, the independent candidates presented “absolutely no factual basis in support of their claims” that Art. 13.50 imposed| unduly burdensome requirements. 349 F. Supp., at 1284. Dunn and Hainsworth relied solely on the minimal 500-signature requirement. This was simply a failure of proof, and [791]*791for that reason we must affirm the District Court’s judgments with respect to these appellants.22
IV
In response to this Court’s decision in Bullock v. Carter, 405 U. S. 134 (1972), invalidating the Texas filing-fee requirements, the state legislature enacted as a temporary measure the McKool-Stroud Primary Financing Law of 1972. Tex. Election Code, Art. 13.08c-1.23 The statute [792]*792generally provided for public financing from state revenues for primary elections of only those political parties casting 200,000 or more votes for governor in the last preceding general election. On its face, therefore, the law precluded any payment of state funds to minor political parties to reimburse them for the costs incurred in conducting their nominating and ballot qualification processes.24 In all, over $3,000,000 was appropriated by the state legislature to the two major political parties to defray their expenses in connection with the 1972 primary elections. Brief for American Party of Texas 19-20, n. 41.
The District Court rejected all constitutional challenges to the law, noting that the statute was designed to compensate for primary election expenses and that “[t]he convention and petition procedure available for small or new parties carries with it none of the expensive election requirements burdening those parties required to conduct primaries,” 349 F. Supp., at 1285. The District Court also emphasized that in response to the State's argument in Bullock v. Carter that state financing of primary elections would necessitate defining those political parties entitled to financial aid and would invite new charges of discrimination, this Court pointed out that under Texas law only those parties whose gubernatorial candidates received more than 200,000 votes were required to conduct primaries and said “[w]e are not persuaded that Texas would be faced with an impossible task in distinguishing [793]*793between political parties for the purpose of financing primaries.” 405 U. S., at 147.25
We affirm the judgment of the District Court. All political parties who desire ballot position, including the major parties, must hold precinct, county, and state conventions. See, e. g., Tex. Election Code, Arts. 13.33, 13.34, 13.35, 13.38, 13.45, 13.45a, 13.47 (1967, Supp. 1973, Supp. 1974). The State reimburses political parties for none of the expenses in carrying out these procedures. New parties and those with less than 2% of the vote in the last election are permitted to nominate their candidates for office in the course of their convention proceedings. The major parties may not do so and must conduct separate primary elections. As we understand it, it is the expense of these primaries that the State defrays in whole or in part. As far as the record before us shows, none of these reimbursed primary expenses are incurred by minority parties not required to hold primaries. They must undergo expense, to be sure, in holding their conventions and' accumulating the necessary signatures to [794]*794qualify for the ballot, but we are not persuaded that the State's refusal to reimburse for these expenses is any discrimination at all against the smaller parties and if it is, that it is also a denial of the equal protection of the laws within the meaning of the Fourteenth Amendment. We are unconvinced, at least based upon the facts presently available, that this financing law is an “exclusionary mechanism” which “tends to deny some voters the opportunity to vote for a candidate of their choosing” or that it has “a real and appreciable impact on the exercise of-the franchise.” Bullock v. Carter, 405 U. S., at 144.
We should also point out that the appellant American Party mounts the major challenge to the primary financing law. The party, however, failed to qualify for the general election ballot; and we cannot agree that the State, simply because it defrays the expenses of party primary elections, must also finance the efforts of every nascent political group seeking to organize itself and unsuccessfully attempting to win a place on the general election ballot.
V
Under Art. 5.05 (Supp. 1974) otherwise qualified voters in Texas may vote absentee in a primary or general election by personal appearance at the county clerk's office or by mail. It is the State's practice, however, to print on the absentee ballot only the names of the two major, established political parties, the Democrats and the Republicans. Raza Unida Party v. Bullock, 349 F. Supp., at 1283-1284.
The District Court sustained the exclusion of minority parties from the absentee ballot, relying on the presumption of constitutionality of state laws, McDonald v. Board of Election Comm’rs, 394 U. S. 802 (1969), and the rationality of not incurring the expense of printing absentee ballots for parties without substantial voter [795]*795support. The Socialist Workers Party, however, satisfied the statutory requirement for demonstrating the necessary community support needed to win general ballot position for its candidates, and with respect to this appellant, the unavailability of the absentee ballot is obviously discriminatory. The State offered no justification for the difference in treatment in the District Court, did not brief the issue here, and had little to say in oral argument to justify the discrimination.
We have twice since McDonald v. Board of Election Comm’rs dealt with alleged discriminations in the availability of the absentee ballot, Goosby v. Osser, 409 U. S. 512 (1973); O’Brien v. Skinner, 414 U. S. 524 (1974). From the latter case, it is plain that permitting absentee voting by some classes of voters and denying the privilege to other classes of otherwise qualified voters in similar circumstances, without affording a comparable alternative means to vote, is an arbitrary discrimination violative of the Equal Protection Clause. Plainly, the District Court in this case employed an erroneous standard in judging the Texas absentee voting law as it was applied in this case. We therefore vacate the judgment of the District Court in No. 72-887 in this respect and remand the Socialist Workers Party case to the District Court for further consideration in light of Goosby v. Osser and O’Brien v. Skinner. In all other respects, that judgment is affirmed, as is the judgment in No. 72-942.
So ordered.