Here is today’s opinion in United States v. Yelloweagle.

An excerpt:

Alden Yelloweagle, the appellant here, was previously convicted of a federal sex offense. When he failed to register as required, he was indicted by federal authorities under the enforcement provision. Mr. Yelloweagle moved to dismiss the indictment for various reasons. Two of the reasons he offered are relevant here. First, he contended that no provision of the Constitution authorizes Congress to require all sex offenders to register. Accordingly, Mr. Yelloweagle
argued, he could not be punished for failing to comply with the requirement. Second, even if the registration requirement was valid, Mr. Yelloweagle contended that the criminal enforcement provision also lacked a jurisdictional
basis and therefore was unconstitutional. The district court denied the motion to dismiss.

In his opening brief on appeal, Mr. Yelloweagle makes no mention of the first argument regarding the registration requirement; he focuses only on the claim that Congress lacks the power to criminalize the failure to register under the
enforcement provision. The government argues that this tactical shift dooms Mr. Yelloweagle’s appeal, for if the registration requirement is presumed to be constitutional, then the criminal provision is valid under the Necessary and Proper Clause. See U.S. Const. art. I, § 8, cl. 18. We agree.