Keyishian v. Board of Regents, 385 U.S.589 (1967), was a United States Supreme Court case in which the Court held that states cannot prohibit employees from being members of the Communist Party and that such laws are overbroad and too vague.
New York state had laws that prohibited state employees from belonging to any organization that advocated the overthrow of the US government, or any organization that was "treasonous" or "seditious". The regents of the State University of New York also required teachers and employees to sign an oath that they were not members of the Communist Party. Some faculty and staff of the University were terminated for refusing to sign the oath. They appealed to the Supreme Court.
Opinion of the Court
The Supreme Court, in a 5-4 decision, overturned the New York state laws prohibiting membership in seditious groups because it was too vague and was overbroad. This largely reversed the 1952 decision in Adler v. Board of Education, in which Irving Adler had been dismissed for the New York City public school system due to a previous connection with the Communist Party USA.