Who's Who in the World of Super PACs? Where does the money come from?

According to research by the Center for Responsive Politics, all liberal super PACs have raised a combined $7.61 million during the first half of 2011 -- with more than 80 percent of their money coming from 23 donors.

Of the $6.24 million donated by these elite donors:

  • 45 percent came from people in the entertainment industry
  • 26 percent came from chief executive officers, excluding those from the entertainment industry
  • 25 percent came from unions
Meanwhile, conservative super PACs have collected $17.61 million so far -- with more than 80 percent of their money coming from 35 donors. 

Of the $14.155 million donated by these elite givers:

  • 66 percent came from chief executive officers
  • 18 percent came from corporate treasuries
  • 16 percent came from individuals employed by Bain Capital, the company Romney founded in the 1980s
Several Republican presidential candidates have also seen their supporters organize super PACs.