The FARC sells cocaine. The Afghan warlords sell heroin. There is no constellation of American political interests for which "Legalize cocaine and heroin" is even remotely conceivable as an achievable policy option.

Incidentally, no matter what you legalize, smuggling remains a viable option for whatever it is you don't. FARC could just as easily be the world's largest kiddie porn or sex slave ring. Afghanistan could sell slaves.

(I am not speaking hypothetically. There are nations which do both. A willingness to do evil plus a local monopoly on coercive force makes for a very profitable combination.)