The Serious Problems of
Mass incarceration is one of the greatest civil rights challenge of the 21st century. Injecting a profit motive into incarceration makes it less likely that we can achieve meaningful reform. Giant corporations rely on full beds and cheap labor, and they can spend enormous amounts of money lobbying for the status quo, or worse.
Keeping the country safe by separating dangerous individuals from the rest of the population is a core government function that cannot be delegated to a private company whose interest is making money. This arrangement violates the social contract that is inherent in a functioning modern democracy.
Justice is Blind - there may be no tenet more central to our justice system than that. However, injecting profits into criminal justice renders that goal non-achievable. Corporations have every incentive to keep people in prison for longer, under worse conditions, and make sure they return by offering fewer rehabilitative programs.
The United States has a dark history of exploiting the lives of disadvantaged groups (usually people of color) for the profit of the powerful - from colonial slavery through coolie labor, black codes, and Jim Crow laws, the government has sanctioned this practice. Locking people up for profit is simply the latest incarnation of slavery.