If the states decided the drug issue, why do you think that would work? Or don't you care if it works or not, as long as that's the way it's done?
I bring this up because, prior to Prohibition, the states alone made the decision whether to be "wet" or "dry" and they split 50-50. Problems arose when the "wet" states illegally smuggled to "dry" states next door.
The "dry" states pressured Congress for assistance and got the Webb-Kenyon Act making this smuggling illegal at the federal level, but that didn't help. Eventually, we got Prohibition.
But you're saying this wouldn't happen with easy-to-smuggle drugs? Or, again, are you saying you just don't care?
I'm not saying it wouldn't happen. I'm sure it would.
I'm also not saying that I don't care.
I'm saying that in many instances it is not a federal issue.