If you're in favor of anything short of complete elimination of all federal laws and regulations on all drugs, you're not in favor of following the Constitution. The Constitution gives the federal government absolutely NO power to criminalize or regulate any drug. The 10th Amendment forbids it, in fact.
Keyphrase is "federal" laws, hey?
Interesting point about the 10th, yet, some would say that it's debatable whether or not complete elimination of all federal laws and regulations would promote the general welfar... but I get what your saying about leaving it up to the States. I have mixed feelings about the FDA's process for approving new drugs and how they're scheduled, for instance, but I think we're better off overall with the approval process.