I guess this applies to any very controversial organization:
there are MD and scientists who are officials of NORML, but it would be a very bad idea to bring this up. not only is this controversial scientifically with doctors on either side of the issue, but it is politically controversial which I feel often interferes with the scientific objectiveness behind this issue. an adcom would probably question your motives of being a member of NORML and would probably shy away from accepting you because their school would essentially be educating someone who would go on to advocate an illegal behavior related to health: something that they would probably not like their graduates to go on to do. do yourself a favor, and avoid this issue with med schools. once you are a physician with expertise and the ability and credibility to truly tackle this issue, you will be much more useful to your cause if you still feel this same way at that point.