Viewpoint neutrality

In United States constitutional law, a public forum is a government-owned property that is open to public expression and assembly.

Forums are classified as public or nonpublic.

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 "[the] 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.

A nonpublic forum is not specially designated as open to public expression. For example, jails, public schools, and military bases are nonpublic forums (unless declared otherwise by the government). Such forums can be restricted based on the content (i.e., subject matter) 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 a pro-life speaker while denying a pro-choice speaker (or vice versa).

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Wikipedia