Heckler's Veto
When hostile audience members effectively silence a speaker by creating a disturbance, and authorities respond by suppressing the speaker rather than the disruption.
The heckler's veto refers to a situation in which the government suppresses a speaker's expression not because of the speech itself, but in response to the actual or anticipated hostile reaction of an audience. The term is used critically — allowing a hostile audience to silence a speaker by reacting with sufficient disturbance is constitutionally disfavored.
The First Amendment generally requires the government to protect speakers from hostile audiences rather than silence the speakers. In Feiner v. New York (1951), the Supreme Court controversially upheld a disorderly conduct conviction against a speaker who refused to stop after police asked him to — citing the threat of violence from a crowd. This decision is widely regarded as a low point in First Amendment jurisprudence.
The modern understanding is that when police can choose between protecting a speaker or yielding to a crowd's desire to silence the speaker, the First Amendment requires protection of the speaker. Venues can impose reasonable security requirements, but cannot use the threat of disruption as a pretext for viewpoint-based exclusions.
Heckler's veto analysis is frequently applied in the campus free speech context, where protest tactics designed to prevent invited speakers from appearing have been criticized as unconstitutional heckler's vetoes.