All drugs should be legalized if we wanted to honor the U.S. Constitution.
However, I think marijuana shines brightly above the rest as a ridiculous prohibition. Because it doesn't kill people. If you smoke it, it MAY lead to cancer, but that's an option.
Virtually any other drug (including alcohol) is infinitely more dangerous. Not just because of the possibility of overdose. But also the reckless behavior the drugs illicit that aren't as common with pot.
If a you get AIDS from a dirty heroin needle, it doesn't mean heroin gave you AIDS. A dirty ass needle did it.
If you get cancer from smoking pot, you got cancer from SMOKING, not the pot.
Don Frye's Mustache > Kimbo's Beard