How about the constitutional alternative - let the States decide intrastate drug policies and have fedgov butt out. You don't support the New Deal Commerce Clause, do you?
I'm not at all fond of the Commerce Clause, but until it is repealed or amended it is the law, just like the first, second and fifth amendments. As far as I'm concerned the fewer things the Feds have a hand in, the better.
Having all the druggies flee to the "tolerant" states has much to be said for it, until it happens to MY state!