Section II: The Doctrinal Evolution — From Clear and Present Danger to Brandenburg

The 1919 Cases and the Founding of Modern Free Speech Law

The Supreme Court's 1919 decisions established the first systematic American constitutional doctrine for distinguishing protected from unprotected political speech. In Schenck v. United States (1919), Justice Oliver Wendell Holmes — writing for a unanimous Court — upheld the conviction of a Socialist Party official who had mailed anti-draft leaflets to conscriptees. Holmes articulated what became known as the 'clear and present danger' test: speech may be restricted when it 'create[s] a clear and present danger that [it] will bring about the substantive evils that Congress has a right to prevent.' (Schenck v. United States, 1919, p. 52). Holmes's famous example — 'the most stringent protection of free speech would not protect a man in falsely shouting fire in a theatre' — has become one of the most frequently quoted passages in American constitutional history.

Eight months later, however, Holmes himself reversed course in dissent. In Abrams v. United States (1919), the Court upheld convictions under the Sedition Act of Russian immigrants who had thrown leaflets from a building in Manhattan criticizing American military intervention against the Bolshevik Revolution. Holmes, joined by Brandeis, dissented vigorously: 'I think that we should be eternally vigilant against attempts to check the expression of opinions that we loathe and believe to be fraught with death, unless they so imminently threaten immediate interference with the lawful and pressing purposes of the law that an immediate check is required to save the country.' (Abrams v. United States, 1919, p. 630) The seeds of a more robust free speech doctrine had been planted.

The Smith Act Era and Its Judicial Limitation

The Smith Act, formally the Alien Registration Act of 1940, was enacted in a period of renewed anxiety about foreign subversion — initially directed at both Nazi and Communist sympathizers (Alien Registration Act, 1940). Its core provision, codified at 18 U.S.C. § 2385, criminalized the knowing advocacy, abetting, advising, or teaching of the necessity or desirability of overthrowing any government of the United States by force or violence. It also criminalized membership in any organization that so advocated.

The Smith Act's constitutional moment came with Dennis v. United States (1951), in which the Supreme Court upheld, 6–2, the convictions of twelve leaders of the Communist Party USA who had been charged with conspiring to advocate the violent overthrow of the government. Chief Justice Vinson's plurality opinion adopted a modified version of the clear and present danger test that asked whether the gravity of the evil, discounted by its improbability, justified the restriction. Given the perceived magnitude of the Communist threat — the Soviet Union had tested its first atomic bomb in 1949, and the Korean War had begun in 1950 — the Court found the balance tipped heavily toward the government (Dennis v. United States, 1951).

Dennis appeared to greenlight aggressive Smith Act enforcement. The Justice Department proceeded to prosecute second-tier Communist Party leaders across the country. But in Yates v. United States (1957), the Court substantially narrowed the holding. Justice Harlan's majority opinion drew a critical distinction: the Smith Act prohibited advocacy of action — organizing and recruiting people to engage in violent overthrow — but not the abstract advocacy of Communist doctrine as a theoretical proposition. The difference between 'we must overthrow the government by force at the earliest practicable opportunity' and 'a proletarian revolution will historically and inevitably produce a classless society' was, legally, the difference between criminal and protected speech (Yates v. United States, 1957). The decision reversed the convictions of fourteen defendants and effectively ended the Smith Act prosecution campaign.

Brandenburg v. Ohio — The Decisive Turning Point

The definitive statement of modern American free speech doctrine came in Brandenburg v. Ohio (1969). The case arose from the prosecution of Clarence Brandenburg, a Ku Klux Klan leader in Ohio, for a speech at a Klan rally that included statements such as 'if our President, our Congress, our Supreme Court, continues to suppress the white, Caucasian race, it's possible that there might have to be some revengeance [sic] taken.' Brandenburg was convicted under Ohio's Criminal Syndicalism Act. A unanimous Supreme Court reversed the conviction.

The Court established the standard that governs to this day: the constitutional guarantees of free speech and free press 'do not permit a State to forbid or proscribe advocacy of the use of force or of law violation except where such advocacy is directed to inciting or producing imminent lawless action and is likely to incite or produce such action.' (Brandenburg v. Ohio, 1969, p. 447) Two requirements must both be satisfied — direction toward imminence AND likelihood of producing that result. Generic political advocacy, however extreme or repugnant, does not meet this test.

The practical consequence of Brandenburg for anti-subversion law was immediate and sweeping. A statute like the Smith Act's advocacy provision — which criminalizes teaching the 'necessity or desirability' of overthrowing the government as an abstract proposition — cannot survive a Brandenburg challenge. A Communist who lectures on Das Kapital, publishes a manifesto, or harangues a crowd about the inevitable proletarian revolution is engaged in protected speech. Brandenburg does not ask whether the ideas are dangerous; it asks whether the specific utterance was aimed at producing imminent illegal action and was likely to do so. Most political advocacy — including most radical political advocacy — fails this test.

Two years before Brandenburg, Albertson v. Subversive Activities Control Board (1965) had gutted the McCarran Internal Security Act's registration requirement. The Act had required members of 'Communist-action organizations' to register with the Subversive Activities Control Board. The Court held that this requirement violated the Fifth Amendment privilege against self-incrimination: requiring someone to register as a Communist was requiring them to admit membership in an organization whose members could be prosecuted under the Smith Act (Albertson v. Subversive Activities Control Board, 1965). The registration mechanism at the heart of the McCarran Act's enforcement architecture was thus eliminated.