This brings up an interesting question. Federal drug laws are unconstitutional - there is no place where the FedGov is given the power to regulate or ban narcotics, plants, etc. etc.
This being the case, can the supremacy clause rightly apply, if it is being applied to declare federal supremacy over state laws, when the FedGov has no power to make such a law, and it rightly falls to the states anywise per the 10th amendment?
That is wrong. Most narcotics cross the southern border of the United States, and THAT alone makes is a federal jurisdiction.