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This graph shows the expenditure by the so-called super PACs in the United States up to May 7, 2012. Super PACs are independent expenditure-only committees, which may raise unlimited sums of money from corporations, unions, associations and individuals, then spend unlimited sums to overtly advocate for or against political candidates. However, direct coordination and communication between political candidates and super PACs is prohibited. Each of the GOP candidates is supported by at least one super PAC. Mitt Romney is supported by the super PAC "Restore Our Future" which has expended about 44.55 million U.S. dollars up to May 7, 2012.