WaPo: (October 15, 2013)

In the past five years, Homeland Security officials have jailed record numbers of immigrants, driven by a little-known congressional directive known on Capitol Hill as the “bed mandate.”

The policy requires U.S. Immigration and Customs Enforcement, or ICE, to keep an average of 34,000 detainees per day in its custody, a quota that has steadily risen since it was established in 2006 by conservative lawmakers who insisted that the agency wasn’t doing enough to deport unlawful immigrants.
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Some of the additional money provided by Congress will be spent filling beds at places such as Karnes County Civil Detention Center, which opened in Texas last year. It holds more than 600 detainees. The low-security facility was built and operated on the government’s behalf by a private contractor, the GEO Group.

Congress’s expanding detention goals have been a boon to the contractors, especially Florida-based GEO Group and Tennessee-based Corrections Corporation of America. The two companies have won hundreds of millions of dollars’ worth of ICE contracts in recent years while lobbying Congress on immigration enforcement issues.
http://www.concordmonitor.com/news/politics/8917739-95/controversial-quota-drives-immigration-detention-boom