1. By denying registration to trademarks that allegedly disparage certain kinds of groups, the federal trademark law (the Lanham Act) discriminates based on viewpoint:

Our cases use the term “viewpoint” discrimination in a broad sense, and in that sense, the disparagement clause discriminates on the bases of “viewpoint.” To be sure, the clause evenhandedly prohibits disparagement of all groups. It applies equally to marks that damn Democrats and Republicans, capitalists and socialists, and those arrayed on both sides of every possible issue. It denies registration to any mark that is offensive to a substantial percentage of the members of any group. But in the sense relevant here, that is viewpoint discrimination: Giving offense is a viewpoint.

We have said time and again that “the public expression of ideas may not be prohibited merely because the ideas are themselves offensive to some of their hearers.” Street v. New York, 394 U. S. 576, 592 (1969). See also Texas v. Johnson, 491 U. S. 397, 414 (1989) (“If there is a bedrock principle underlying the First Amendment, it is that the government may not prohibit the expression of an idea simply because society finds the idea itself offensive or disagreeable”) [more cases omitted] …