Speech that, if it falls into one or more of several categories, is treated by the Supreme Court as entitled to no (or lessened) constitutional protection because of the harm to society such utterances may cause.
In Chaplinsky v. New Hampshire
Justice Frank Murphy defined several classes of speech that are not protected by the Constitution.
Justice Murphy’s approach has been characterized as a two-tier theory of the First Amendment. Socially valuable speech is protected, but certain categories are unworthy of constitutional protection. After Chaplinsky, as the Court became more sensitive to free speech issues, it emphasized narrowly and precisely defining these categories, as well as introducing into each of these categories (except obscenity) certain First Amendment exceptions.
In 1973 in Miller v. California
Although the Court found no First Amendment value in obscenity, it consistently held that not all sexual depictions or utterances were the equivalent of obscenity. Thus, in Sable Communications v. Federal Communications Commission
Although Chaplinsky was not overruled, after that case, the Court never upheld a conviction solely for “fighting words” directed at public officials. In R.A.V. v. City of St. Paul
Although not mentioned in Justice Murphy’s Chaplinsky listing, incitement to illegal activity was also traditionally considered unprotected speech. Much of modern First Amendment jurisprudence was developed in the context of speech advocating violent overthrow of the government, starting with Justice Oliver Wendell Holmes’s famous clear and present danger test
In Brandenburg v. Ohio
The Court also held that certain categories of speech, although not totally unprotected, may be entitled to lesser First Amendment protection. This group includes sexually explicit but nonobscene speech (in certain contexts), symbolic speech (communicative conduct such as marching, picketing, wearing arm bands, or burning a U.S. flag), and commercial speech (advertising and similar commercial expression).
Abraham, Henry J., and Barbara A. Perry. Freedom and the Court. 7th ed. New York: Oxford University Press, 1998. Greenwalt, Kent. Fighting Words. Princeton, N.J.: Princeton University Press, 1995. Lewis, Anthony. Make No Law: The Sullivan Case and the First Amendment. New York: Random House, 1991.
Brandenburg v. Ohio
Chaplinsky v. New Hampshire
Clear and present danger test
First Amendment speech tests
New York Times Co. v. Sullivan
Obscenity and pornography