Everyone knows how much corruption spread in the government at ALL levels during alcohol prohibition. Corruption is even more pervasive now under intrinsically flawed drug prohibition.
First, there are a few things you should know. Often, the biggest detractors of a thing are "in the closet." After a bit of research on the Internet you can find examples of priests who have raged against prostitutes, but then are caught with a prostitute. Or the fairly recent example of the minister from Colorado who preached hatred of gays, but was outed by his gay prostitute.
So just because you hear someone rage against drugs, don't be fooled. She, or he, could very well be a closet drug user. In fact you might be able to have a little fun with them. The next time they rage against drugs, just ask them if they are addicted to drugs. If they say "yes" well perhaps there is some help for them. But if they say "no," just use the line their ilk uses on others, "denial is the first sign of an addiction." But you'd better be prepared to duck quickly! :-)
There are many, many sources you can find online which document the corruption which alcohol prohibition inspired, as well as the current systemic corruption intrinsic in drug prohibition. Wikipedia has some, Professor Hanson documents some, and at StopTheDrugWar.org they have a few categories: Corruption, Financial Corruption, Government Corruption, and Police Corruption.
So, with that in mind, here are some questions worth asking yourself, and others.