Under the federal Sex Offender Registration and Notification Act (SORNA), sex offenders must register as sex offenders and must update their registration when they travel from one state to another. David Hall, a convicted sex offender in New York, moved to Virginia, where he did not update his registration. He was charged with violating SORNA. He claimed that the statute is unconstitutional, arguing that Congress cannot criminalize interstate travel if no commerce is involved. Is his argument reasonable? Why or why not? [United States v. Hall, 591 F.3d 83 (2d Cir. 2010)]