JimDandy, under which enumerated power do you think this falls?
It is justified by the commerce clause. And while I stipulate it's not much of a limitation, it is limited by that clause. It does specifically state
numerous times.in interstate or foreign commerce
While I am open to the idea that this would be overturned on a challenge, it hasn't been so yet, so without that successful challenge, it is presumptively legal and constitutional, and within the Congress's enumerated power to regulate interstate commerce.