I was just listening to NPR, the "Constitutionalist" on the program was arguing that the Federal Government can bar the creation and use of drugs, even on a purely private level, thanks to the Commerce Clause, because the drugs could end up on the market.
Shouldn't there be a burden of proof that the person who grows and smokes his own drugs was distributing drugs to others? Not just for a lower sentence, but to prevent Federal prosecution of any kind. If I grow something and consume it,* it's impossible to claim that it applies to Interstate Commerce.
*Note, I don't do any kind of drugs.