A public forum, also called an open forum, is open to all expression that is protected under the First Amendment. Streets, parks, and sidewalks are considered open to public discourse by tradition and are designated as traditional public forums. The government creates a designated public forum when it intentionally opens a nontraditional forum for public discourse. Limited public forums, such as municipal meeting rooms, are nonpublic forums that have been specifically designated by the government as open to certain groups or topics. Traditional public forums cannot be changed to nonpublic forums by governments. The use of public forums generally cannot be restricted based on the content of the speech expressed by the user. Use can be restricted based on content, however, if the restriction passes a strict scrutiny test for a traditional and designated forum or the reasonableness test for a limited forum. Also, public forums can be restricted as to the time, place and manner of speech. In the 1972 case Grayned v. City of Rockford, the Supreme Court found that "The nature of a place, the pattern of its normal activities, dictate the kinds of regulations of time, place, and manner that are reasonable." In determining what is reasonable, the Court stated that " crucial question is whether the manner of expression is basically incompatible with the normal activity of a particular place at a particular time." Thus, protesters have the right to march in support of a cause, but not on a public beach during the middle of the day with bullhorns.
Nonpublic forums
A nonpublic forum is not specially designated as open to public expression. For example, jails, public schools, and military bases are nonpublic forums. Such forums can be restricted based on the content of the speech, but not based on viewpoint. Thus, while the government could prohibit speeches related to abortion on a military base, it could not permit an anti-abortion speaker while denying an abortion rights speaker. Regardless of the type of forum, any exclusion must be done on a viewpoint neutral basis. Exclusion based on the speaker’s viewpoint is unconstitutional.
In several important cases, courts have decided that what appeared to be viewpoint-based censorship in a forum was actually the government's tailoring of its own speech, which need not be viewpoint neutral, and that no forum was in fact created. When a governmental entity, such as a public broadcaster, employs the speech of ordinary citizens to further its goals, the government speech doctrine blocks citizens' First Amendment claims that the government set up a forum for them, and unconstitutionally suppressed speech in it.
The 1988 decision in Hazelwood v. Kuhlmeier relied on the notion of a public forum in determining the degree to which a public school newspaper that has not been determined as such a forum can be protected by the First Amendment. The Court decided that such newspapers are subject to a lower level of First Amendment protection than independent student newspapers established as forums for student expression.
