Yeah, I'm not sure what I was thinking, given that this is a federal case. I think I was thinking that the due process clause being reinforced by the fourteenth amendment would negate some of the arguments about colonial prohibitions on gun ownership by slaves or freed men (the government actually tried to argue that recently) because the preceeding thirteenth amendment, but somehow wires got crossed and I was distracted with work and the heat.
Anyhow, I assume you read my previous post, so I would argue that the vagueness doctrine which is derived from due process clearly applies, given the power it allows law enforcement to selectively enforce it. And I believe that there was even a recent case in which a judge ruled that even a one time use of a controlled substance would be sufficient, which makes selective enforcement even more probable.
But the bigger issue to me, is that even under Heller, flatly prohibiting any user of a controlled substance such as marijuana from possessing an arm that was involved in any way with interstate commerce is defacto stripping that person of a fundamental right without due process, which means strict scrutiny should be applied. I don't think there is anybody on this board who would say that the government has a compelling interest in stripping cancer patients of their second amendment rights unless they fundamentally disagree that it is actually a right.