U.S. Rep. Joe Baca of California, shown at the 2008 Democratic National Convention, learned the power of superPACs firsthand this year, when he lost for the first time since he was elected in 1999. Jae C. Hong/AP hide caption

itoggle caption Jae C. Hong/AP

A supporter of President Barack Obama raises his arms as it is announced that Obama was re-elected during an election night watch party in Chicago. Jerome Delay/AP hide caption

itoggle caption Jerome Delay/AP

The Campaign to Defeat Barack Obama, a small-donor PAC, has launched a bus tour to reach conservative voters in hotly contested states, while trying to raise money to launch an anti-Obama TV ad. Yfat Yossifor/Courtesy of Mlive.com hide caption

itoggle caption Yfat Yossifor/Courtesy of Mlive.com

U.S. Sen. Sherrod Brown (right), D-Ohio, debates his Republican challenger, Ohio state Treasurer Josh Mandel, at the City Club in Cleveland on Oct. 15. Tony Dejak/AP hide caption

itoggle caption Tony Dejak/AP

Las Vegas casino magnate Sheldon Adelson watches a performance at the Sands Cotai Central in Macau in April. Kin Cheung/AP hide caption

itoggle caption Kin Cheung/AP