It is hardly a novel perception that compelled disclosure of affiliation with groups engaged in advocacy may constitute as effective a restraint on freedom of association as the forms of governmental action in the cases above were thought likely to produce upon the particular constitutional rights there involved. This Court has recognized the vital relationship between freedom to associate and privacy in one's associations. When referring to the varied forms of governmental action which might interfere with freedom of assembly, it said in American Communications Assn. v. Douds, supra, at 339 U. S. 402: 'A requirement that adherents of particular religious faiths or political parties wear identifying armbands, for example, is obviously of this nature.'
Compelled disclosure of membership in an organization engaged in advocacy of particular beliefs is of the same order. Inviolability of privacy in group association may in many circumstances be indispensable to preservation of freedom of association, particularly where a group espouses dissident beliefs. Cf. United States v. Rumely, 345 U. S. 56-58 (concurring opinion).
See American Communications Assn. v. Douds, 339 U. S. 382, 339 U. S. 402. In the domain of these indispensable liberties, whether of speech, ...