EVANSTON, Illinois, Sept. 18 -- The Northwestern University Institute for Policy Research posted the following news: * * * Prosecutor Politics * The United States incarcerates more people than any nation in the world, according to internationally available data. Today's mass incarceration can be tracked back to the 1970s, when President Richard Nixon's "law and order" agenda and "tough on crime" messaging resonated with a public anxious about crime and social unrest. That shift ushered in harsher sentencing policies, expanded policing power more PR