[cat199]

op said 'intrastate', not sure if that relates to your point.

an argument can be made that intrastate impacts interstate, but not sure where the threshold lies - AFAIK you don't have alcohol companies suing in court to oppose local alcolhol regulations on this basis, etc, as an example (though I'm sure they lobby heavily).

[int_19h]

That threshold is defined by Gonzales v. Raichs at the moment, and it's low enough that it's possible for the feds to ban growing cannabis purely for personal consumption.

For state and local laws, it would be a matter of the corresponding state constitution - but it's less of an issue on that level, because state constitutions are generally not written in such a way as to restrict the power of the government to a few explicitly enumerated things.