[robertpaulsen]

"And exactly how a drug gets used should be the decision of the federal government, not the state governments because...? "

... because Congress has exercised its power under the Commerce Clause to regulate drugs.

"It seems to me that exactly how an individual and his doctor decide to practice medicine is more among the objects which, in the ordinary course of affairs, concern the lives, liberties, and properties of the people, and the internal order, improvement, and prosperity of the State, and thus a state government concern."

I agree. Unless, of course, that practice includes the dispensing of controlled substances. Then it becomes a federal concern.

[BikerNYC]

... because Congress has exercised its power under the Commerce Clause to regulate drugs.

Then why was a constitutional amendment needed for alcohol to be prohibited?