There! I said it! In public! Conservative me!
My rationale is simple, though imprecise. The social costs of legal marijuana, however high, would be less than the social costs of illegal marijuana. I have no fancy studies to prove the assertion. But if you look around, especially if you put Mexico in the equation, the conclusion becomes obvious.
The argument isn’t that the “war on drugs has failed.” I accept the logic, offered me 10 years ago by the Drug Enforcement Administration, that “war” is the wrong metaphor. A “war” means maximum resources are devoted to winning. We have never had a real war on drugs.