We are really seeing what happens when a society becomes bound up with laws upon laws upon laws with none going away and hundreds being added every year. Pretty soon the laws are in direct conflict.
Marijuana has been outlawed on a federal level in this country since 1937. Prior to that 30 states had already outlawed it. Is the use of marijuana a state or federal issue? I would think that until the Supreme Court rules otherwise, the Federal law supersedes state law.