Freedom of Speech
The right to speak freely is guaranteed by the First Amendment to the U.S. Constitution and state constitutions.
The Constitution protects against viewpoint-based restrictions, such as political speech, and laws amounting to "prior restraints on speech," which could prevent someone from speaking for fear of retribution. Protected speech can range from oral and written expression to non-verbal forms of communication, such as artistic renderings. It includes not only the act of speaking or not speaking, but also the dissemination of information. However, the level of protection varies depends on the type of speech being regulated and the governmental interest at stake.
Generally speaking, government cannot regulate speech on the basis of the message being conveyed. Content-based restrictions are subject to the highest level of judicial review, strict scrutiny, which means that they must be justified by a "compelling state interest," be "narrowly tailored," and constitute the "least restrictive means" of achieving the governmental interest.
Content-neutral restrictions, in comparison, such as the typical historic preservation law, are subject to "time, place and manner" restrictions, otherwise known as intermediate scrutiny. As such, governmental restrictions will be upheld if they are narrowly tailored, serve a significant governmental interest, and leave open ample alternative channels for communication.
Special rules apply to specific forms of speech, such as obscenities, hate speech, libel and slander. Laws may be challenged as facially unconstitutional, as applied in a particular case, and as impermissibly overbroad.
To date, the regulation of signs, news racks, sculptures and murals in local historic districts, as well as restrictions on the use of tables, distribution of leaflets, and street performances in historic districts, have all been upheld against free speech challenges as reasonable "time, place and manner" restrictions.