So you mean states can't just make up their own laws which are violations of Federal law?
Where did I say that? States can't violate restrictions placed on them by the Constitution, which includes "no slavery" but not "no pot."
But with pot, the slavery isn't put on the users so much as on those of us who have to pay for them to sit around all day drawing welfare instead of working.
I am firmly against slavery, and so we shouldn't let any drug addicts make us into slaves.