Well, here's my two cents on the issue.
I can see no logical reason why it should'nt be a legal intoxicant (For recreational use as well as medicinal). The impact on ones health is no greater than that of alcohol or cigarets, and its mental alterations are much milder and indeed, more desireable.
When was the last time you heard of a guy getting high on pot and beating his wife and kids when he otherwise wouldn't? How about getting drunk and doing the same? I can't count the number of times I've seen a guy, who is normally a great person, become a beligerant ass after just two beers. Marijuana's effects on behavior and judgement are far less severe and almost the complete opposite. It makes you happier, and nicer and lowers inhebitions just a tiny bit, just enough for someone who is otherwise anti-social and reclusive to actually go out and enjoy the company of others. But you won't wind up trying to pick a fight with your best friend or wind up sleeping with the bearded woman.
That said, there are few things with as much history as marijuana. There was a point in time when the entire human civilization depended upon it for war, travel, and comerce. Clothes, sails, rope, arrows, lumber, medicine...you name it, it can be made with hemp.
What really gets me though, is how it came to be illegal. The secretary of the freaking tresurey launched a propaganda campaign full of bold faced lies and missinformation that scared the masses into outlawing it. They actually claimed it turned people into insane, violent, sex addicted psychopaths....which is now known to be complete crap.