A Project of The Annenberg Public Policy Center

Independence USA

A left-leaning super PAC founded and financed by former New York City Mayor Michael Bloomberg.

American Crossroads/Crossroads GPS

Affiliated Republican advocacy groups formed with the help of Ed Gillespie, former chairman of the Republican National Committee, and Karl Rove, an adviser to President George W. Bush.

Congressional Leadership Fund

A super PAC focused on maintaining and expanding the Republican majority in the House of Representatives.

Americans for Prosperity

A major force behind the tea party movement, this conservative/libertarian group was founded by billionaire businessman David Koch.

Senate Majority PAC

A Democratic super PAC created to “protect and expand the Democratic majority in the U.S. Senate.”

Club for Growth Action

The super PAC of the conservative Club for Growth, which advocates for limited government.