This chapter traces a series of stark, occasionally stunning historical reversals by the Supreme Court in interpreting the Free Speech Clause. It highlights doctrines under which the Court treats almost all content-based regulation of speech as constitutionally suspect. That position, which draws little support from research into original constitutional understandings, reflects a commitment – increasingly embraced by conservative justices of a libertarian stripe – to the principle that the Free Speech Clause bars the government from censoring speech based on fears that the speech might prove persuasive to its audience. The resulting doctrine, which makes the United States an outlier among liberal democracies, provides robust protection for a good deal of “hate speech,” some outright lies, commercial advertising, and corporate expenditures to promote political candidates. This chapter also discusses cases that have held that the Free Speech Clause protects a right to “freedom of association” that lacks any clear textual basis. It concludes by considering cases involving speech rights in “managerial domains” in which the government performs functions, such as providing public education, that it could not perform successfully without engaging in content-based regulation of speech.

The right to free expression is of special importance for any discussion of the legal and social enforcement of morality. This is true for two main sets of reasons. First, the free expression and communication of ideas in a political society profoundly affects its ethical environment. The right to free expression, or more precisely the social condition that is brought about by the adequate recognition and protection of the right, is itself a public good. Second, the free expression and communication of ideas, especially ideas relevant to politics, is widely considered to be a condition of government legitimacy. Governments that wrongly deny their subjects the right to freely express their ideas forfeit a claim to rule over them. This chapter engages with both sets of reasons, which are referred to as the public good consideration and the legitimacy consideration, respectively, with an eye toward clarifying the grounds of the right to free expression and the limits to its scope. The chapter pays special attention to the issue of whether the right to free expression extends to so-called dangerous speech; that is, speech that advocates for violence against the government and/or certain targeted groups.