“Since most law-abiding citizens had no contact with the parole system, it was not a priority with the state legislatures. And since most of the state's prisoners were either poor or black, and unable to use the system to their advantage, it was easy to hit them with harsh sentences and keep them locked up. But for an inmate with a few connections and some cash, the parole system was a marvelous labyrinth of contradictory laws that allowed the Parole Board to pass out favors.”