Second, § 922(q) contains no jurisdictional element which would ensure, through case-by-case inquiry, that the firearm possession in question affects interstate commerce. For example, in United States v. Bass, 404 U.S. 336 (1971), the Court interpreted former 18 U.S.C. § 1202(a), which made it a crime for a felon to “receiv[e], posses[s], or transpor[t] in commerce or affecting commerce . . . any firearm.” 404 U.S., at 337. The Court interpreted the possession component of § 1202(a) to require an additional nexus to interstate commerce both because the statute was ambiguous and because “unless Congress conveys its purpose clearly, it will not be deemed to have significantly changed the federal-state balance.” The Bass Court set aside the conviction because although the Government had demonstrated that Bass had possessed a firearm, it had failed “to show the requisite nexus with interstate commerce.” Id., at 347. The Court thus interpreted the statute to reserve the constitutional question whether Congress could regulate, without more, the “mere possession” of firearms. Unlike the statute in Bass, § 922(q) has no express jurisdictional element which might limit its reach to a discrete set of firearm possessions that additionally have an explicit connection with or effect on interstate commerce.
Although as part of our independent evaluation of constitutionality under the Commerce Clause we of course consider legislative findings, and indeed even congressional committee findings, regarding effect on interstate commerce, the Government concedes that “[n]either the statute nor its legislative history contain[s] express congressional findings regarding the effects upon interstate commerce of gun possession in a school zone.” We agree with the Government that Congress normally is not required to make formal findings as to the substantial burdens that an activity has on interstate commerce. See McClung. But to the extent that congressional findings would enable us to evaluate the legislative judgment that the activity in question substantially affected interstate commerce, even though no such substantial effect was visible to the naked eye, they are lacking here. . . . .