Comment by awinder

What you have to understand as a baseline is that AEI is a partisan think-tank, so they're not telling truths or exploring the spectrum of interpretations, they're coming at any given issue with an ideologically driven mantra. And in this case, that mantra is that the commerce clause of the constitution, which states:

  The Congress shall have power ... To regulate commerce with foreign nations, and among the several states, and with the Indian tribes;

means that congress has exclusive power to regulate interstate commerce. This actually has a ton of case precedent around it, and speaking as neutrally as possible, the courts have never simply ruled that only the federal government has the power to regulate commerce amongst the states.