Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances.
Vagueness is a due process vice that can be brought into play with regard to any criminal and many civil statutes, 1 but it has a special signficance when applied to governmental restrictions of speech: fear that a vague restriction may apply to one's speech may deter constitutionally protected speech as well as constitutionally unprotected speech. Vagueness has been the basis for voiding numerous such laws, especially in the fields of loyalty oaths, 2 obscenity and indecency, 3 and restrictions on public demonstrations. 4 It is usually combined with the overbreadth doctrine, which focuses on the need for precision in drafting a statute that may affect First Amendment rights; 5 an overbroad statute that sweeps under its coverage both protected and unprotected speech and conduct will normally be struck down as facially invalid, although in a non-First Amendment situation the Court would simply void its application to protected conduct. 6