themselves substantially affect interstate commerce.”). In upholding § 16913 under the Commerce Clause and the Necessary and Proper Clause, the Second Circuit noted that (1) “§ 16913 does not exist in a vacuum” but rather complements § 2250; (2) by the time SORNA was enacted, every state had a sex offender registry, so SORNA was not solely focused on creating a registry; and (3) the enforcement provision in § 2250(a) would not affect a sex offender convicted in state court who did not travel between states or countries. Guzman, 591 F.3d at 90-91. “Congress‟s goal was not simply to require sex offenders to register or to penalize the failure to do so,” but instead “to make sure sex offenders could not avoid all registration requirements just by moving to another state.” Id. at 91. The court in Guzman concluded that  [r]equiring sex offenders to update their registrations due to intrastate changes of address or employment status is a perfectly logical way to help ensure that states will more effectively be able to track sex offenders when they do cross state lines. To the extent that § 16913 regulates solely intrastate activity, its means „are reasonably adapted to the attainment of a legitimate end under the commerce power,‟ and therefore proper.  Id. (quoting Raich, 545 U.S. at 37 (Scalia, J., concurring in the judgment)) (further internal quotation marks and citation omitted).   The Fifth Circuit concluded that § 2250 and § 16913 “are clearly complementary: without § 2250, § 16913 lacks federal criminal enforcement, and without § 16913, § 2250 has no substance.” United States v. Whaley, 577 F.3d 254, 259 (5th Cir. 2009). That court also recognized that SORNA was focused “on the problem of sex offenders escaping their registration requirements through interstate travel.” Id. The court in Whaley  conclude[d] that requiring sex offenders to register both before and