Some super PACs receive untraceable money, campaigns dominated by super rich, study finds

Six out of the top 10 fundraising super PACs have received untraceable donations. In total, 20 percent of super PACs received untraceable donations in 2011.

A study entitled "Auctioning Democracy" also found that the super rich give a large amount of the funding received by super PACs. This skews American politics, it concluded, because wealthy donors have different life experiences and political preferences than other citizens.

The report was completed by the non-profit groups Demos and U.S. Public Interest Research Group, which are pushing for stronger campaign donation rules.

It outlined what campaign staff have known since 2010 -- the campaign season is being dominated by a group of super-rich citizens willing to spend big money on the candidates they support.