When the Law Goes Too Far: Understanding Overbreadth and Vagueness

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In Cincinnati, a group of three or more people could commit a crime by gathering on a sidewalk and behaving in a way that annoyed passersby. The Supreme Court struck down that ordinance on June 1, 1971.

A group deciding whether to gather faced two questions: what did “annoying” mean, and could the city prohibit its gathering in the first place? The first is a question of vagueness, which asks whether a law gives fair notice and limits arbitrary enforcement. The second is a question of overbreadth, which asks whether a law prohibits too much protected expression.

Two different ways a law can cross the line

The First Amendment overbreadth doctrine permits a challenge to a law that reaches protected speech even when the challenger’s own conduct may be unprotected. The objection is to the law’s reach: a prohibition can capture expression the Constitution protects along with conduct government may punish.

Vagueness review asks whether ordinary people have a reasonable opportunity to know what is prohibited and whether enforcers have explicit standards. These are separate safeguards: notice addresses the person deciding how to act, while enforcement standards address the officials deciding whom to stop or punish.

A single law can have both defects: the Supreme Court found the Cincinnati ordinance vague because its standard could not be determined and overbroad because it authorized punishment of constitutionally protected conduct.

Why speech gets an unusual overbreadth challenge

The Supreme Court permits overbreadth challenges partly because a law’s existence can cause people outside the case to refrain from constitutionally protected speech. Those people may simply stay silent and never come to court, so waiting for each of them to be prosecuted would leave the law’s deterrent effect in place.

The Supreme Court has said a court will strike down a law as overbroad if it prohibits a substantial amount of protected speech relative to its plainly legitimate sweep, meaning its lawful applications. The Court requires unconstitutional applications to be realistic rather than fanciful and substantially disproportionate to the law’s lawful applications. Otherwise, courts address unconstitutional applications case by case. Striking down a whole law would block its enforcement even against conduct government has constitutional authority to prohibit.

In Broadrick v. Oklahoma, decided June 25, 1973, the challengers were state employees charged with partisan political activity, including soliciting money among coworkers for their superior. They conceded that the restriction was constitutional as applied to that activity. Their argument instead depended on what the statute might do to protected activity in other situations. The Supreme Court found the restriction not substantially overbroad and left any remaining overbreadth to case-by-case analysis.

Why an unclear law violates due process

The Fifth Amendment’s due process protection applies to the federal government and guards against deprivation of life, liberty or property without due process of law. The Fourteenth Amendment imposes the same prohibition on state governments. The question is not whether a rule contains any ambiguity, but whether it is so uncertain that people cannot tell what it prohibits or enforcers have no clear standard to apply.

In Grayned v. City of Rockford, the Supreme Court explained that vague laws can trap innocent people by failing to provide fair warning. It also warned that vague rules leave basic policy decisions to police, judges and juries on an ad hoc, subjective basis. When unclear restrictions approach First Amendment freedoms, uncertainty can cause people to avoid a wider range of activity than a clearly marked boundary would require.

The Supreme Court has said that language cannot offer mathematical certainty, and that reasonable breadth can be consistent with adequate clarity. In Grayned, the Court held that Rockford’s antinoise ordinance was not vague because it prohibited only actual or imminent, willful interference with normal school activity and did not broadly invite discriminatory enforcement. Disruption could be measured against the normal activities of the school, a context that gave fair notice.

Economic regulation receives a less strict vagueness test partly because its subject matter is often narrower and businesses can be expected to consult relevant law before acting. Courts also tolerate more imprecision in rules carrying civil penalties than criminal penalties because the consequences are less severe. The required precision depends on what the rule does and what is at stake.

What the landmark cases actually decided

In Coates v. City of Cincinnati, the Supreme Court explained that conduct annoying to some people does not annoy others, so the ordinance supplied no standard of conduct at all. The Court also found that the ordinance authorized punishment of constitutionally protected assembly. The ruling did not equate every annoying act with protected expression; it rejected that ordinance’s method of deciding which gatherings were criminal.

In Papachristou v. City of Jacksonville, decided February 24, 1972, the Supreme Court reversed the judgment upholding convictions under Jacksonville’s vagrancy ordinance. The ordinance’s categories included people wandering or strolling without lawful purpose, habitual loafers and disorderly persons. It treated broad descriptions of a person’s presence or way of life as grounds for punishment, rather than giving a precise account of a prohibited act. The Court held it void for vagueness because it failed to give fair notice and encouraged arbitrary and erratic arrests and convictions.

Vagueness safeguards apply both to laws defining crimes and to laws fixing criminal sentences. The Armed Career Criminal Act imposes an increased prison term on a defendant with three prior convictions for a violent felony. Its catchall, known as the residual clause, defined a violent felony to include any felony involving conduct that presents a serious potential risk of physical injury to another.

In Johnson v. United States, the Supreme Court said two features of that clause made it unconstitutionally vague. Judges had to estimate risk from an imagined ordinary case of a crime rather than from real-world facts, and the clause left uncertain how much risk it takes for a crime to qualify as a violent felony.

The Supreme Court decided Johnson on June 26, 2015, and held that increasing a sentence under the residual clause violated due process. The decision did not call into question the Act’s four listed offenses, which are burglary, arson, extortion and crimes involving the use of explosives, or the rest of its definition of a violent felony.

Johnson also rejected the idea that a vague provision is constitutional merely because some conduct clearly falls within it.

How courts decide whether to strike a law down

A facial challenge contests a statute as a whole, whereas an as-applied challenge asks whether the law is unconstitutional in a particular case.

A state statute should not be invalidated as a whole for overbreadth if the state courts can readily interpret it more narrowly, or if its deterrent effect on protected expression is not real and substantial. The law’s legal meaning matters, not just the broadest everyday meaning its words might bear.

State courts supply authoritative interpretations of their state’s laws; the Supreme Court cannot authoritatively construe state legislation. A narrowing interpretation must be readily supported by the statute; a federal court cannot rewrite a state law to make it constitutional.

Interpretation came first in United States v. Hansen, which involved a federal immigration law. Helaman Hansen promised hundreds of noncitizens a path to U.S. citizenship through “adult adoption,” which offers no such path, and was convicted under a provision that forbids encouraging or inducing a noncitizen to come to, enter or live in the United States unlawfully. On June 23, 2023, the Supreme Court rejected his overbreadth challenge. It read the provision to forbid only the purposeful solicitation and facilitation of specific acts known to violate federal law. Solicitation means intentionally encouraging an unlawful act; facilitation means assisting someone with the intent to further an offense. That construction made the prohibition narrower than a general ban on encouraging or supporting someone.

In Moody v. NetChoice, LLC, the Supreme Court said a court weighing a facial First Amendment challenge must determine the law’s full set of applications, evaluate which are constitutional and which are not, and compare the two. On July 1, 2024, it set aside the appeals court judgments on Florida and Texas laws regulating large internet platforms and sent the cases back, because neither appeals court had conducted the proper facial analysis. A prominent disputed application cannot stand in for the whole law when the requested remedy would reach the whole law.

Sending the cases back did not end the Florida lawsuit. On June 18, 2026, the federal district court in that case denied four motions for summary judgment, which are requests to decide a case without a trial.

What a challenge can change, and what it cannot

Overbreadth’s concern for people who are not in court does not turn the courts into a general complaint desk for anyone who dislikes a statute. A challenge still needs a dispute that a court can hear. A person seeking to challenge a law before it is enforced can show the required concrete injury by planning conduct that arguably involves a constitutional right and that the law arguably forbids, while facing a credible threat of prosecution. An actual arrest or prosecution is not always a prerequisite to challenging a threatened enforcement action. The relevant distinction is between a concrete enforcement threat and a disagreement with a rule in the abstract.

The most useful questions about a rule are concrete: what protected activity does it reach, what notice does it give, and what constrains the person enforcing it? A successful challenge can leave other prohibitions intact, as Johnson did, so the scope of the decision matters as much as the label attached to the law.