Nonsense!
Just because you believe in states rights does not mean there is no place for the Federal government at all. Interstate Commerce is one of the few areas in which a Federal government is necessary. That is of course if it really is about interstate business.
Righto!
Oddly enough, that’s exactly how a Republican Congress and President could have constitutionally put slavery on the road to extinction.
Just prohibit interstate commerce in slaves. Shut up in their individual little markets, slavery would have withered quickly, at least in the upper and border slave states.
You appaently seem to think imposing a federal Slave Code on inhabitants of territories would have been an exercise of the Interstate Commerce clause. I’m curious why you think that’s the case.