Interesting Vagueness Case That the Court Is Being Asked to Hear

From the cert. petition:

In United States v. Salerno, 481 U.S. 739, 745 (1987), this Court held that to maintain a facial challenge, a plaintiff must establish that "no set of circumstances exists under which the Act would be valid." The federal courts of appeals are starkly split on the question of whether this rule was relaxed by the Court in the context of vagueness cases in Johnson v. United States, 135 S. Ct. 2551 (2015), and Sessions v. Dimaya, 138 S. Ct. 1204 (2018). The Fourth and Eighth Circuits have answered in the affirmative. See Kolbe v. Hogan, 849 F.3d 114, 148 fn.19 (4th Cir. 2017); United States v. Bramer, 832 F.3d 908 (8th Cir. 2016). By contrast, the Second Circuit expressly insisted below that no such relaxation has taken place. Copeland v. Vance, 893 F.3d 101, 113 fn.3 (2d Cir. 2018). The question presented is: Whether a plaintiff need show that a law is vague in all of its applications to succeed in a facial vagueness challenge.

You can read the government's response, the reply, and the amicus briefs here. (I signed one, though did not write it.) You can also see the debate about whether the case is moot—10 days ago, the New York Legislature repealed the underlying statute, but people could still be prosecuted for their pre-repeal conduct (yes, that's the legal rule in most jurisdictions with regard to statutory repeals), and gravity knives (defined using the same definition that is being challenged as vague) remain forbidden on New York City subways and buses. Very interesting stuff.

The Court will be considering the case at its conference Thursday.