The controlled substance act violated the constitution as it regulates even intrastate trade of drugs. It relies on the tyrannical Wickard V Filburn ruling which says intrastate commerce is actually interstate commerce. The charges against Ross relied on law that flagrantly transgress the 10th amendment of the US constitution as written and as enforced.
This is why they needed an actual amendment to nationally ban, say, home made liquor.
I don't think that legal argument is accurate, but hey, I'm not a lawyer and neither are you.