Did you read Chris Hedges' scathing account of the percentage of cases pleaded out which force innocent people to serve time mostly on threat that if they take their matter to trial and lose, they'll serve yet more time? The entire system has become a fraud, and a big reason for that outcome was the War on Drugs.
By pushing thousands of people into the Criminal Justice system, judges, time slots, and public defenders were absolutely overwhelmed.
The inevitable prison time pushed onto so many persons allowed private firms with lobbying muscle in Washington, D.C. to push through more and more prison building.
This idea of creating a problem to feign a solution... is the basis for the growth of a domestic inmate population and it also explains how the ruse of a war on terrorism created the pretext for an enormously militarized and muscular covert police state.