Senator Ted Cruz has an excellent essay in the Harvard Law Review Forum entitled Limits on the Treaty Power. Here is a taste: The Necessary and Proper Clause does not give Congress power to implement treaties in a way that contravenes the structural limitations on the federal government’s powers …. The President should not be able to make any treaty — and Congress should not be able to implement any treaty — in a way that displaces the sovereignty reserved to the states or to the people. Cruz thus argues that Justice Holmes’s opinion in Missouri v. Holland must be...