How does making the stuff illegal handle gangbangers on meth, exactly?

The anti-legalization crowd seems to hold it as an article of faith that criminalizing drug use results in less drug use. The arguments always come down to some variation on, "Freedom is good, but drugs are bad, so sometimes it's worth making them illegal."

I think you need to show that criminalizing physically addictive drugs like heroin, PCP, meth, etc. actually reduces their use. The evidence available so far from places like Portugal seems to indicate the opposite, although the data is far from clear.

I mean, your PCP example is from a place where all of this stuff is already highly illegal. How is that not an argument against criminalization?