I think you guys are missing part of the picture here. Sure being under the influence and shooting is dumb, whether drugs, legal or otherwise, or alcohol.
Besides most of the people I have seen trying to get medical MJ have a physical disability that I personally wouldn't want to have a gun either. The people I have dealt with were physically disabled (weakness, temors ect normally because of another illness) or had vision issues (cataracts, glucoma, near blindness). Do you want someone who can't see very well or can't aim properly/hold the gun up wandering around armed? My wife's aunt is a medically retired CA prison guard and has a CCW pretty much for life. She could probably qualify for CA's medical MJ program, if she hasn't already. She can barely keep the G36 she carries on target for more than a shot or two and can JUST see the target at 15yds. She is SUPPOSED to qualify with it every couple years to maintain it but hasn't fired the complete course since I've known her. Love her to death but wouldn't want to be around if she actually had to use the bloody thing.
FQ-Last time I checked if your were USING MJ or any other medication meant you were to some extent UNDER THE INFLUENCE of SOMETHING. The affects also have some duration. Most that are part of those kinds of programs don't use one day and not the next. It is a daily thing, if not more than once a day. Alcohol is processed in the body MUCH faster than THC so that isn't a realy good analogy.