The opinion focused on the defendant's facial vagueness challenge to the definition of a machinegun.
Long story very short, the Court held the definition was not unconstitutionally vague: "By focusing on whether a device has a specific configuration of objective features that, absent a minor defect, would give it the capacity to shoot automatically, the phrase a “weapon which . . . is designed to shoot . . . automatically” provides both sufficient notice as to what is prohibited and sufficient guidance to prevent against arbitrary enforcement."
For me, the most important part of the opinion comes in a footnote: "The facial invalidations in these three cases do, however, refute the Government’s assertion that, outside the First Amendment context, only as-applied vagueness challenges may be considered."
The three cases are Johnson, Davis, and Dimaya. This footnote is a longtime coming. Use it to bring facial challenges.
Finally, it is worth noting the Court agreed the convictions were multiplicitous:
Here, the Government concedes that § 922(o) does not require proof of any element that is not also required under § 5861(d). The former statute requires possession of an item that qualifies as a machinegun with knowledge of the essential characteristics that make that item a machinegun, see 18 U.S.C. §§ 922(o), 924(a)(2), and the latter statute requires all of those same elements (plus an additional element concerning the lack of registration), see 26 U.S.C. §§ 5845(a)(6), 5845(b), 5861(d), 5871. The § 922(o) charge is therefore a lesser-included offense of the § 5861(d) charge. The Government further concedes that neither statute (nor any other provision of law) indicates that Congress authorized cumulative punishments to be imposed simultaneously under both provisions. Because “[o]ne of the convictions, as well as its concurrent sentence, is unauthorized punishment,” one of them must be vacated.
