BUCKLEY v. VALEO 1 Per Curiam that is only one of the factors that must be considered. Some of the criteria are not precisely indicative of even that factor. Age," or past political success, for instance, may typically be associated with parties that have a high probability of success. But not all long-established parties are winners-some are consistent losers-and a new party may garner a great deal of support if it can associate itself with an issue that has captured the public's imagination. None of the criteria suggested is precisely related to the other critical factor that must be considered, the possibility that disclosure will impinge upon protected associational activity. An opinion dissenting in part from the Court of Appeals' decision concedes that no one line is "constitutionally required." 91 It argues, however, that a flat exemption for minor parties must be carved out, even along arbitrary lines, if groups that would suffer impermissibly from disclosure are to be given any real protection. An approach that requires minor parties to submit evidence that the disclosure requirements cannot constitutionally be applied to them offers only an illusory safeguard, the argument goes, because the "evils" of "chill and harassment ... are largely incapable of formal proof." 92 This dissent expressed its concern that a minor party, particularly a 90 Age is also underinclusive in that it would presumably leave longestablished but unpopular parties subject to the disclosure requirements. The Socialist Labor Party, which is not a party to this litigation but which has filed an amicus brief in support of appellants, claims to be able to offer evidence of "direct suppression, intimidation, harassment, physical abuse, and loss of economic sustenance" relating to its contributors. Brief for Socialist Labor Party as Amicus Curiae 6. The Party has been in existence since 1877. 91 171 U. S. App. D. C., at 258, 519 F. 2d, at 907 n. 1 (Bazelon C. J.). 92 Id., at 260, 519 F. 2d, at 909. See also Developments in the Law-Elections, 88 Harv. L. Rev. 1111, 1247-1249 (1975).