Democratic U.S. House candidate Andrew Janz raised more than $4 million in three months as part of his effort to unseat U.S. Rep. Devin Nunes, R-Calif.), part of a wave of record-breaking fundraising hauls by Democratic candidates. Justin Sullivan/Getty Images hide caption
Jeb Bush speaks to an audience of voters on Feb. 18 in Columbia, S.C. Bush dropped out of the GOP presidential race two days later, after finishing a distant fourth in the state's primary. Spencer Platt/Getty Images hide caption
Democratic mayoral candidate Jim Kenney benefited from a super PAC that helped him win in the city's Democratic primary election. Matt Slocum/AP hide caption
Rick Perry ended his presidential campaign Sept. 11, but there was $13 million left in the bank of a superPAC supporting him. The superPAC says it's given donors their money back. Scott Olson/Getty Images hide caption
Demonstrators march in the snow outside the White House during a rally against the Supreme Court's decision five years ago in favor of Citizens United, which allows private citizens and corporations to make unlimited donations for political campaigns. Nicholas Kamm/AFP/Getty Images hide caption
"Exploratory" Republican presidential candidate Jeb Bush speaks April 17 at the First in the Nation Republican Leadership Conference in Nashua, N.H. His super PAC — Right to Rise — is aiming to raise $100 million dollars by June 1. Brian Snyder/Reuters/Landov hide caption
Sen. Rand Paul, R-Ky., center, meets with members of the Londonderry Fish and Game Club in Litchfield, N.H., on Jan. 14. Paul was one of three GOP presidential hopefuls who attended Sunday's semiannual gathering of David and Charles Koch's donor network in California. Jim Cole/AP hide caption
Businessman Tom Steyer listens during a meeting to announce the launch of a group called Virginians for Clean Government in September 2013. Steve Helber/AP hide caption
Comedian Stephen Colbert, left, holds a rally with former GOP presidential candidate Herman Cain at the College of Charleston in South Carolina. Richard Ellis/Getty Images hide caption
Texas governor Rick Perry speaks on June 18, 2011 in New Orleans, Louisiana. Justin Sullivan/Getty Images hide caption