Opinion of the Court
contributions to the “marketplace of ideas.” Virginia v. Hicks, 539 U. S. 113, 119 (2003). To guard against those harms, the overbreadth doctrine allows a litigant (even an undeserving one) to vindicate the rights of the silenced, as well as society’s broader interest in hearing them speak. Williams, 553 U. S., at 292. If the challenger demonstrates that the statute “prohibits a substantial amount of protected speech” relative to its “plainly legitimate sweep,” then society’s interest in free expression outweighs its interest in the statute’s lawful applications, and a court will hold the law facially invalid. Ibid.; see Hicks, 539 U. S., at 118–119.
Because it destroys some good along with the bad, “[i]nvalidation for overbreadth is ‘ “strong medicine” ’ that is not to be ‘casually employed.’ ” Williams, 553 U. S., at 293. To justify facial invalidation, a law’s unconstitutional applications must be realistic, not fanciful, and their number must be substantially disproportionate to the statute’s lawful sweep. New York State Club Assn., Inc. v. City of New York, 487 U. S. 1, 14 (1988); Members of City Council of Los Angeles v. Taxpayers for Vincent, 466 U. S. 789, 800–801 (1984). In the absence of a lopsided ratio, courts must handle unconstitutional applications as they usually do—case-by-case.
III
A
To judge whether a statute is overbroad, we must first determine what it covers. Recall that §1324(a)(1)(A)(iv) makes it unlawful to “encourag[e] or induc[e] an alien to come to, enter, or reside in the United States, knowing or in reckless disregard of the fact that such coming to, entry, or residence is or will be in violation of law.”[1] The issue is
- ↑ Although the statutory terms are not coextensive, we use “alien” and “noncitizen” as rough equivalents here. See 8 U. S. C. §1101(a)(3); Barton v. Barr, 590 U. S. ___, ___, n. 2 (2020) (slip op., at 3, n. 2).
