Drugs are not that bad. Not enough to warrant widespread abuse of power. Not enough to take me away from my wife. And the power is abused. By cops, by district attorneys, by judges on the take.
Corruption follows illegality.
There are corrupt cops in your neighborhood. There are corrupt judges, airline pilots, Representatives, Senators, bureaucratic heads, border patrol agents, Coast Guard personnel. Wherever there is power, corruption follows. America has more people in prison, per capita, than any other nation. More than China, more than Russia, more than Iran or Afghanistan or Iraq or Serbia or North Korea.