The “substantial effects doctrine” of the New Deal interpretation of the Commerce Clause effectively destroyed any distinction between interstate and intrastate commerce. They consider anything they want to regulate “interstate commerce”, regardless of whether it’s bought or sold across state lines, or even bought or sold at all. It doesn’t even have to actually exist.
Except the SCOTUS has, with the Obamacare decision, undermined the misinterpretations of the Interstate Commerce Clause, the General Welfare Clause (used by LBJ to create the welfare state), and the Necessary and Proper Clause.
It will take a while for the other shoe to drop, and will depend who the next POTUS is, and whether he appoints conservatives to replace liberals on the court.