Watch an ex-cop explain why: "The War on Drugs is a joke."
At 3:47 he demolishes the idea that we can enforce away the drug trade.
At 5:54 he explains how the drug problem can be fixed, and at 7:30 he points out how we can keep people from doing drugs without criminalizing them.
At 11:08 he points out the hypocrisy of prohibition.
At 12:28 he talks about the money we would make/not lose by ending prohibition.
At 13:46 he makes a very important point about the very first case of prohibition.