[mburns]

Except prohibition was a constitutional amendment, and the Supremecy Clause of said Constitution says that an amendment take precedence over any state (or federal) law.

Drug prohibition laws are federal, but not part of the constitution. Very different, legally speaking.

[emiliobumachar]

The difference you pointed out seems to make the precedent stronger, favoring the theory that states may just contradict the feds on the drug issue.