I've been trying to boil this down to one concise paragraph -
Despite the American public's majority opinion that Marijuana should be legalized, there remains one prohibitive malevolent force keeping it from happening
- MONEY -
Big Pharma does not you to grow a drug in your back yard for free which takes away their market share, so they write checks to congress to keep it banned.
The DEA does not want a major reason for their budget and operations to disappear, so they lobby heavily to keep it banned.
The Prison Industry, lastly but not least, does not want the laws which keep them so busy maintaining the largest prison population in the world to be taken away, so they write checks to congress to keep it banned.
OK, so that wasn't a paragraph, but I had to bust it up for readability. But that's it, and I DEFY ANYONE to prove me wrong. Any and all moral arguments against it fail and dissolve in the face of Alcohol, cigarettes, and prescription drugs.
The only remaining reason, is money. And in reality, Laws which are maintained for the sake of a self interested well monied minority against the majority will of the over all public, are unjust laws.