We are trying to put laws in place to stop tobacco smokers from smoking. And DWI laws for drunk driving etc are also becoming more and more strict.
Personally I wouldn't want to green-light a "legal marijuana" without a breathalyser type test. DUI laws are already in place for it, just need the test.
With that... I really see no real difference between marijuana and alcohol.
http://www.houseparent.net/informati...ohol-marij.htm
My problem with legal cannabis comes down to having a high people out in public.
Most pot smokers I know don't see a problem with lighting up early in the day. While getting drunk in the morning after waking up is seen as a horrid abuse... Some pot smokers simply do not see it that way.