Because of its popularity and its relatively benign effects. It isn't a drug that will induce addiction or cause long term health damage (well... that we know o

Because of its popularity and its relatively benign effects. It isn't a drug that will induce addiction or cause long term health damage (well... that we know of). And it certainly seems much less harmful than the other psychoactive drug that we have legalized (alcohol). But I think popularity is probably the biggest factor. Its when you see your own family/friends' family being destroyed by criminal convictions resulting from marijuana use does it create a strong push to legalize the stuff.