The Supreme Court overturned the conviction of a man under a criminal syndicalism statute, ruling that the advocacy of illegal action could be punished only if it was likely to produce imminent lawless action.

Clarence Brandenburg, a Ku Klux Klan member, was convicted of violating a criminal syndicalismCriminal syndicalism statute for appearing in a television report brandishing a shotgun and advocating racial strife. The Supreme Court, in a unanimous unsigned per curiam decision, found it unconstitutional for a state to impose a criminal syndicalist statute punishing the mere advocacy of the overthrow of the U.S. government.Speech, freedom of;Brandenburg v. Ohio[Brandenburg v. Ohio]Assembly and association, freedom of;Brandenburg v. Ohio[Brandenburg v. Ohio]

This ruling overturned Whitney v. California[case]Whitney v. California[Whitney v. California] (1927), in which the Court had upheld a similar statute, and brought an end to fifty years of largely futile efforts to make the vague clear and present danger test of Schenck v. United States[case]Schenck v. United States[Schenck v. United States] (1919) work in varying circumstances. At times, this test allowed the government to prosecute for speech that demonstrated a bad tendency or, as in Dennis v. United States[case]Dennis v. United States[Dennis v. United States] (1951), for plans to publish unpopular views. By insisting that the government must demonstrate that the action was likely to incite imminent lawless action before prosecuting, the Court provided a much more concrete test that substantially strengthened free speech and validated the imminence test suggested in Justice Oliver Wendell Holmes’s dissent in Abrams v. United States[case]Abrams v. United States[Abrams v. United States] (1919).

Abrams v. United States

Bad tendency test

Clear and present danger test

Criminal syndicalism

Dennis v. United States

First Amendment

Gitlow v. New York

Schenck v. United States

Symbolic speech

Whitney v. California