Whitney v. California, 274 U.S. 357 (1927), was a United States Supreme Court decision upholding the conviction of an individual who had engaged in speech that raised a threat to society.

Facts
Anita Whitney, a member of a distinguished California family, was convicted under the state's 1919 Criminal Syndicalism Act for allegedly helping to establish the Communist Labor Party, a group the state charged was devoted to teaching the violent overthrow of government. Whitney claimed that it had not been her intention, nor that of other organizers, that the party become an instrument of violence.

Result
The question before the court was whether the 1919 Criminal Syndicalism Act of California violated the Fourteenth Amendment’s “due process” and “equal protection” clauses. The Court, by a 9-0 vote, held that it did not and upheld Whitney's conviction. Justice Sanford wrote for the seven-justice majority opinion, and invoked the Holmes test of "clear and present danger" but went further. The state, he declared, has the power to punish those who abuse their rights to speech "by utterances inimical to the public welfare, tending to incite crime, disturb the public peace, or endanger the foundations of organized government and threaten its overthrow." In other words, if words have a "bad tendency" they can be punished.

The Brandeis concurrence
The Whitney case is most noted for Justice Louis Brandeis's concurrence, which many scholars have lauded as perhaps the greatest defense of freedom of speech ever written by a member of the high court. Justice Brandeis and Justice Holmes concurred in the result because of the Fourteenth Amendment questions, but there is no question that the sentiments are a distinct dissent from the views of the prevailing majority and supported the First Amendment.

Holmes in Abrams had been willing to defend speech on abstract grounds, believing that unpopular ideas should have their opportunity to compete in the "marketplace of ideas." But Brandeis had a much more specific reason for defending speech, and the power of his opinion derives from the connection he made between free speech and the democratic process. Citizens have an obligation to take part in the governing process, and they can only fulfill this obligation if they can discuss and criticize governmental policy fully and without fear. If the government can punish unpopular views, then it cramps freedom, and in the long run, will strangle democratic processes. Thus, free speech is not only an abstract virtue, but a key element that lies at the heart of a democratic society.

Implicitly, Brandeis here moves far beyond the clear and present danger test, and he insists on what some have called a "time to answer" test: no danger flowing from speech can be considered clear and present if there is full opportunity for discussion. While upholding full and free speech, Brandeis tells legislatures that while they have a right to curb truly dangerous expression, they must define clearly the nature of that danger. Mere fear of unpopular ideas will not do.

Justice William O. Douglas believed that had Brandeis lived longer, he would have abandoned the clear and present danger test; Whitney is in fact the precursor to the position Douglas and Hugo L. Black would take in the 1950s and 1960s, that freedom of speech is absolutely protected under the First Amendment. Brandeis does not go that far here, and his views were ultimately adopted by the Court in Brandenburg v. Ohio, 395 U.S. 444 (1969), which explicitly overruled Whitney.

Of note, Miss Whitney was later pardoned by the Governor of California based on Justice Brandeis' concurring opinion.

The Court's decision in the Whitney case was overruled in 1969 in Brandenburg v. Ohio.