A principle of JUDICIAL REVIEW that holds that a law is invalid if it punishes constitutionally protected speech or conduct along with speech or conduct that the government may limit to further a compelling government interest.
Legislatures sometimes pass laws that infringe on the FIRST AMENDMENT freedoms of religion, speech, press, and peaceable assembly. When a legislature passes such a law, a person with a sufficient interest affected by the legislation may challenge its constitutionality by bringing suit against the federal, state, or local sovereignty that passed it. One common argument in First Amendment challenges is that the statute is overbroad.
Under the overbreadth doctrine, a statute that affects First Amendment rights is unconstitutional if it prohibits more protected speech or activity than is necessary to achieve a compelling government interest. The excessive intrusion on First Amendment rights, beyond what the government had a compelling interest to restrict, renders the law unconstitutional.
If a statute is overbroad, the court may be able to save the statute by striking only the section that is overbroad. If the court cannot sever the statute and save the constitutional provisions, it may invalidate the entire statute.
The case of Brockett v. Spokane Arcades, Inc., 472 U.S. 491, 105 S. Ct. 2794, 86 L. Ed. 2d 394 (1985), illustrates how the overbreadth doctrine works. At issue in Brockett was an OBSCENITY statute passed by the state of Washington. The statute declared to be a moral NUISANCE any place where lewd films were shown as a regular course of business and any place where lewd publications constituted a principal part of the stock in trade. Lewd matter was defined as being obscene matter, or any matter that appeals to the prurient interest. Under the statute the term prurient was defined as tending to incite lasciviousness or lust.
The Supreme Court in Brockett ruled that the Washington statute was overbroad because it prohibited lust-inciting materials. According to the Court, because lust is a normal sexual appetite, materials that include an appeal to lust enjoy First Amendment protection. Therefore, a statute that prohibits any material arousing lust is constitutionally overbroad.
The remedy in the Brockett case was not complete invalidation of the moral nuisance law. The Court directed that the reference to lust be excised from the statute and stated that the rest of the statute was valid. The statute, though originally overbroad, was still valid because it contained a severability clause and was still effective after its overbroad portion was struck.