As of mid-1991, there were about 20,000 prisoners in privately managed local, State, and Federal facilities representing about 1.5 percent of all prisoners. Until recently, most private corrections contracts have been for relatively low-security facilities housing special populations. New Mexico, for example, contracts for the operation of a women's facility and California for return-to-custody centers for parole violators. Texas contracts with the Corrections Corporations of American and the Wackenhut Corrections Corporation for several minimum-to-medium security prerelease centers. States now entering into private contracts for male, general population prisoners include Louisiana and Tennessee. In addition, the U.S. Marshals Service and the Immigration and Naturalization Service have contracts in place for minimum - and mixed-security detention. The strongest selling point of private prison companies involves reduced costs. Policymakers are attracted by claims that privately operated prison facilities can save 5 to 15 percent over their government-run counterparts. Even so, doubts linger about cost savings as a justification for private prisons. Further, public employee labor unions oppose prison privatization; they claim that cost savings are short-term and that profit does not have a place in penology. It is noted that at least 17 States have enabling legislation for the private management of correctional facilities.