A lot of the measures that fill the prisons today (mandatory minimums, three strikes, aggressive prosecution, no parole), started back before the private prison industry even existed. So why on earth should I believe that "for-profit prison lobbyists" have anything to do with these issues? It's a totally nonsense explanation.
I don't know why there is this need to believe that ordinary voters aren't the ones ultimately culpable for the state of the justice system in the U.S. It's soccer moms and dads, shop owners, etc., that have been the backbone of "tough on crime" and "just say no" for decades.
[1] Getting rid of for-profit prisons was part of former Maryland governor O'Malley's presidential platform.