The way I look at it, drugs are illegal...
...because.
Back around the turn of the century, people started to get disturbed by asian "opium dens," and they finally figured out that opioids were addictive... Bam!
In the 20s and 30s, they started worrying about their children consorting with negroes to smoke hemp.
BAM!
In the sixties, darn near everything but pennicillin came under fire.
Whammo!
Today, we've got a couple of major industries. Illicit unregulated importation and distribution, and the law enforcement side that is supposed to stop it. The black marked has ALWAYS won in the long run. Crime DOES pay.
Legalize it, all of it, and put it either in liquor stores or pharmacies. Take the hollywod and bling-bling out of it. The black market is essentially gone, since the opportunity for massive profits are gone. Sure, there's still _some_ bootlegging between high-tax and low-tax states, but you'll always see that - you don't have people doing drive-bys on competing bars or liquor stores...
Law enforcement is VERY worried about legalization. Not because of an anticipated increase in crime. Because of an anticipated DECREASE in need for law enforcement. There's always going to be petty theft by people addicted to one thing or another. But I'm guessing that'll even drop somewhat.