395 U.S. 444 (1969)
Brandenburg v. Ohio is a foundational First Amendment decision that reshaped the constitutional boundary between protected advocacy and punishable incitement.
Does the First and Fourteenth Amendments permit a state to criminalize mere advocacy of the use of force or law violation—without proof that the advocacy is directed to inciting or producing imminent lawless action and likely to produce such action?
The First and Fourteenth Amendments prohibit states from forbidding or punishing advocacy of the use of force or law violation except where the advocacy is: (1) directed to inciting or producing imminent lawless action, and (2) likely to incite or produce such action. Mere abstract advocacy of violence or illegal conduct is protected; only intentional, imminent, and likely incitement may be proscribed.
Ohio's Criminal Syndicalism statute, as applied to Brandenburg's speech, violates the First and Fourteenth Amendments because it punished mere advocacy and did not require proof that the speech was directed to inciting or producing imminent lawless action and likely to do so. The conviction was reversed.
Brandenburg is the leading incitement case and the cornerstone of modern free speech doctrine on advocacy of illegal conduct. It rejects earlier 'bad tendency' and amorphous 'clear and present danger' formulations, centering the analysis on intent, imminence, and likelihood. The decision ensures that the government cannot punish inflammatory or extremist political rhetoric absent proof that it seeks to spark and is likely to cause immediate unlawful action. This doctrine has been applied to protect provocative protest speech (e.g., Hess v. Indiana) and robust political advocacy (e.g., NAACP v. Claiborne Hardware). For law students, Brandenburg illustrates the strong presumption against content-based regulation, the narrow window for criminalizing advocacy, and the precision required in drafting and enforcing public order statutes.