opinion: Per Curiam.
  On March 4, 1966, the Attorney General petitioned the Subversive Activities Control Board for an order, after appropriate hearings, requiring the W. E. B. DuBois Clubs of America to register with the Attorney General as a Communist-front organization. On April 26, 1966, before hearings were held, appellants attempted to bypass the Board by suing in the District Court. Appellants' complaint in the District Court alleged that the Communist-front registration provisions of the Act were unconstitutional. The complaint also alleged that the “very pendency of these administrative proceedings . . . has resulted and will continue to result . . . in immediate and irreparable injury to fundamental constitutional rights . . . .” Appellants asked the District Court for an order declaring the Communist-front registration provisions unconstitutional and also for an order enjoining the Attorney General and the SACB from enforcing them. A three-judge District Court, convened on appellants’ motion, dismissed the complaint because appellants had failed to exhaust their administrative remedies. This appeal followed.
  Before there may be proceedings to punish appellants for failure to register with the Attorney General, the SACB must first find that the DuBois Clubs is a Communist-front organization and issue an order to that effect. The Act provides for a full evidentiary hearing which is to be held in public. Appellants may be represented by counsel, offer oral or documentary evidence, submit rebuttal evidence, and conduct cross-examination. The SACB must make a written report and state its finding of fact. If appellants are aggrieved by the Board’s order, they may obtain review in the United States Court of Appeals for the District of Columbia Circuit which may set aside the order if it is not “supported by the preponderance of the evidence.” Upon motion of a party, the Court of Appeals may order the Board to take additional evidence. Of course, if the Board and the Court of Appeals find that the Act does cover appellants, they may challenge its constitutionality either as applied or on its face. Judgments of the Court of Appeals are reviewable by this Court on certiorari.
  It is evident that Congress has provided a way for appellants to raise their constitutional claims. But appellants, denying that they are within the coverage of the Act, wish to litigate these claims in an injunctive proceeding in the District Court. The effect would be that important and difficult constitutional issues would be decided devoid of factual context and before it was clear that appellants were covered by the Act. We have previously refused to decide the constitutionality of the very provisions involved here because it was not clear that the Act would be applied to the objecting parties. American Committee for Protection of Foreign Born v. SACB, 380 U. S. 503, Veterans of the Abraham Lincoln Brigade v. SACB, 380 U. S. 513. Similarly, the District Court should not be forced to decide these constitutional questions in a vacuum.
  Appellants rely on Dombrowski v. Pfister, 380 U. S. 479 (1965), to support their contention that the usual rule requiring exhaustion of administrative remedies should not apply in this case. In Dombrowski, however, the constitutional issues were presented in a factual context. Upon a record demonstrating a history of harassment of appellants in connection with their exercise of First Amendment rights, the Court ordered a federal district court to issue an injunction against pending criminal prosecutions under state statutes. This Court held the statutes “void on their face,” and it concluded that, in the circumstances of that case, if appellants were required to submit to a criminal prosecution, the injury to First Amendment freedoms which had already taken place would be compounded. Accordingly, the Court allowed appellants to assert their claims in an equitable proceeding.
  In this case, the complaint and .the affidavits constitute no more than conclusory allegations that the purpose of the threatened enforcement of the Act was to “harass” appellants and that harassment was the intended result of the Attorney General’s announcement that he had filed a petition with the SACB. Further, appellants are not being forced to assert their claims in a criminal prosecution. As the court below made clear, “Congress has made careful provision that no tangible sanctions can come into play until the facts have been explored in open hearing [before the Board] and the courts have scrutinized what they show, both in their adequacy to support a registration order and in their constitutional impact upon the statute itself.” In the context of this case, we decline to require the court below to permit substitution of an injunctive proceeding for the civil proceeding which Congress has specifically provided.
  The motion to affirm is granted and the judgment is affirmed. Affirmed.
  The term “Communist-front organization” is defined in § 3 (4) of the Internal Security Act of 1950, 64 Stat. 989, 50 U. S. C. § 782 (4). Communist-front organizations are required to register with the Attorney General. 50 U. S. C. § 786. When a Communist-front organization does not register, the Attorney General may petition the SACB for an order requiring registration. 50 U. S. C. §792.
  On April 27, 1966, appellants also filed with the Board a motion to dismiss the Attorney General’s petition. The Board denied this motion and, subsequently, on August 18, 1966, appellants filed an answer to the Attorney General’s petition. According to the District Court, the DuBois Clubs “(1) denied generally that it was a Communist-front organization within the meaning of the Act, and (2) denied various allegations of fact made by the Attorney General in the petition.”
  Appellants attacked the provisions, 50 U. S. C. §§ 786 (b), (c), and (d), “on their face and as applied” as violations of Art. I, § 9, cl. 3, Art. Ill, and the First, Fifth, Eighth, Ninth, Tenth, Thirteenth, Fourteenth, and Fifteenth Amendments of the Constitution. Although the Communist-front provisions have been upheld by the District of Columbia Circuit, American Committee for Protection of Foreign Born v. SACB, 117 U. S. App. D. C. 393, 401, 331 F. 2d 53, 61 (1963), reversed on other grounds, 380 U. S. 503 (1965); Veterans of the Abraham Lincoln Brigade v. SACB, 117 U. S. App. D. C. 404, 413, 331 F. 2d 64, 73 (1963), reversed on other grounds, 380 U. S. 513 (1965); Weinstock v. SACB, 118 U. S. App. D. C. 1, 331 F. 2d 75 (1963); Jefferson School of Social Science v. SACB, 118 U. S. App. D. C. 2, 331 F. 2d 76 (1963), their constitutionality has not been specifically determined by this Court, American Committee for Protection of Foreign Born v. SACB, 380 U. S. 503 (1965); Veterans of the Abraham Lincoln Brigade v. SACB, 380 U. S. 513 (1965). Cf. Aptheker v. Secretary of State, 378 U. S. 500 (1964).
  However, the District Court did stay further Board proceedings pending this Court’s disposition of the case.
  50 U. S. C. §794 (a).
  See National Council of American-Soviet Friendship v. SACB, 116 U. S. App. D. C. 162, 322 F. 2d 375 (1963).
  See 50 U. S. C. §§792 (d), (g), 793 (a).
  Cf. Rescue Army v. Municipal Court, 331 U. S. 549, 568-585 (1947).
  See, e. g., Myers v. Bethlehem Shipbuilding Corp., 303 U. S. 41, 50-51 (1938); Macauley v. Waterman S. S. Corp., 327 U. S. 540, 543-545 (1946); Aircraft & Diesel Corp. v. Hirsch, 331 U. S. 752, 771-774 (1947); Allen v. Grand Cent. Aircraft Co., 347 U. S. 535, 553 (1954); Boire v. Greyhound Corp., 376 U. S. 473, 481-482 (1964).
  See 50 U. S. C. §§793 (b), 794.
choices: comity: civil rights comity: criminal procedure comity: First Amendment comity: habeas corpus comity: military comity: obscenity comity: privacy comity: miscellaneous comity primarily removal cases, civil procedure (cf. comity, criminal and First Amendment); deference to foreign judicial tribunals assessment of costs or damages: as part of a court order Federal Rules of Civil Procedure including Supreme Court Rules, application of the Federal Rules of Evidence, Federal Rules of Appellate Procedure in civil litigation, Circuit Court Rules, and state rules and admiralty rules judicial review of administrative agency's or administrative official's actions and procedures mootness (cf. standing to sue: live dispute) venue no merits: writ improvidently granted no merits: dismissed or affirmed for want of a substantial or properly presented federal question, or a nonsuit no merits: dismissed or affirmed for want of jurisdiction (cf. judicial administration: Supreme Court jurisdiction or authority on appeal from federal district courts or courts of appeals) no merits: adequate non-federal grounds for decision no merits: remand to determine basis of state or federal court decision (cf. judicial administration: state law) no merits: miscellaneous standing to sue: adversary parties standing to sue: direct injury standing to sue: legal injury standing to sue: personal injury standing to sue: justiciable question standing to sue: live dispute standing to sue: parens patriae standing standing to sue: statutory standing standing to sue: private or implied cause of action standing to sue: taxpayer's suit standing to sue: miscellaneous judicial administration: jurisdiction or authority of federal district courts or territorial courts judicial administration: jurisdiction or authority of federal courts of appeals judicial administration: Supreme Court jurisdiction or authority on appeal or writ of error, from federal district courts or courts of appeals (cf. 753) judicial administration: Supreme Court jurisdiction or authority on appeal or writ of error, from highest state court judicial administration: jurisdiction or authority of the Court of Claims judicial administration: Supreme Court's original jurisdiction judicial administration: review of non-final order judicial administration: change in state law (cf. no merits: remand to determine basis of state court decision) judicial administration: federal question (cf. no merits: dismissed for want of a substantial or properly presented federal question) judicial administration: ancillary or pendent jurisdiction judicial administration: extraordinary relief (e.g., mandamus, injunction) judicial administration: certification (cf. objection to reason for denial of certiorari or appeal) judicial administration: resolution of circuit conflict, or conflict between or among other courts judicial administration: objection to reason for denial of certiorari or appeal judicial administration: collateral estoppel or res judicata judicial administration: interpleader judicial administration: untimely filing judicial administration: Act of State doctrine judicial administration: miscellaneous Supreme Court's certiorari, writ of error, or appeals jurisdiction miscellaneous judicial power, especially diversity jurisdiction