Rep. Todd Akin, R-Mo., says Rep. Paul Ryan, R-Wis., the GOP vice presidential candidate, asked him to end his Senate bid after recent comments he made referring to "legitimate rape." Jeff Roberson/AP hide caption

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Artur Davis, with his wife, Tara, concedes the Democratic gubernatorial race in Birmingham, Ala., in 2010. Since losing that race, he has become a Republican and moved to Virginia. Mark Almond/AP hide caption

itoggle caption Mark Almond/AP

Rep. Paul Ryan, R-Wis., at a campaign event on June 18 in Janesville, Wis. Ryan, Mitt Romney's running mate, has made sure his constituents haven't been left out of federal programs like the stimulus. Evan Vucci/AP hide caption

itoggle caption Evan Vucci/AP

Businessman John Brunner is making his first run for elective office in the Missouri Senate race. Brian Naylor/NPR hide caption

itoggle caption Brian Naylor/NPR

Former Minnesota Gov. Tim Pawlenty and GOP presidential candidate Mitt Romney campaign in Las Vegas on Oct. 17, 2011. Ethan Miller/Getty Images hide caption

itoggle caption Ethan Miller/Getty Images