The following flavor of comment has been made many times on HN, but since I’m halfway through Michelle Alexander’s book The New Jim Crow I’m in the mood for making it again here:
The drug war has been “successful”, because its goal was to incarcerate, disenfranchise, extort, terrorize, and break apart the families of minorities so that America could retain a racial hierarchy after the civil rights movement. This hierarchy is advantageous to the ruling class because they can continue to exploit poor whites economically, keep them off the bottom of the hierarchy, and retain their political support.
When Reagan declared a War on Drugs in 1982, less than 2% of Americans viewed drug use as the most important issue facing the nation. In 1989 that number was at 64%, all without a significant increase in drug usage. (Rates for drug crimes did increase, because criminality was the effect of the War on Drugs, not its cause.)