Rep. Paul Ryan, R-Wis., when he was campaigning as the 2012 Republican vice presidential nominee. Michael Sears /MCT /Landov hide caption

itoggle caption Michael Sears /MCT /Landov

Vice President Biden and his Republican opponent, Rep. Paul Ryan of Wisconsin, participate in the vice presidential debate at Centre College in Danville, Ky., Thursday. Charlie Neibergall/AP hide caption

itoggle caption Charlie Neibergall/AP

Sen. Lloyd Bentsen (D-Texas) shakes hands with Sen. Dan Quayle (R-Ind.) before their vice presidential debate at the Omaha Civic Auditorium in Omaha, Neb., on Oct. 5, 1988. Ron Edmonds/AP hide caption

itoggle caption Ron Edmonds/AP

Weeds were already growing in the parking lot outside the GM assembly plant in Janesville, Wis., on May 4, 2009. Scott Olson/Getty Images hide caption

itoggle caption Scott Olson/Getty Images

A delegate shows his support for Paul Ryan on a night dominated by the acceptance speech of the vice presidential nominee. Becky Lettenberger/NPR hide caption

itoggle caption Becky Lettenberger/NPR

Republican vice presidential nominee Paul Ryan and his wife, Janna (at right), along with two of their children and his mother, Betty, on stage Wednesday in Tampa. Brendan Smialowski /AFP/Getty Images hide caption

itoggle caption Brendan Smialowski /AFP/Getty Images

Republican vice presidential candidate, Rep. Paul Ryan waves with his family Wednesday at the GOP convention in Tampa. Also on stage: his daughter Liza, sons Charlie and Sam Ryan, wife Janna and mother Elizabeth. Win McNamee/Getty Images hide caption

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Republican presidential candidate Mitt Romney speaks at a town hall meeting in Grand Junction, Colo., on July 10. Romney said he has "nothing hidden" in his taxes. Nicholas Kamm/AFP/Getty Images hide caption

itoggle caption Nicholas Kamm/AFP/Getty Images

House Budget Committee Chairman Paul Ryan, R-Wis., shakes hands with Federal Reserve Chairman Ben Bernanke at the close of the committee's hearing on the state of the economy in February 2011. J. Scott Applewhite/AP hide caption

itoggle caption J. Scott Applewhite/AP

Republican presidential candidate Mitt Romney (right) and running mate Rep. Paul Ryan of Wisconsin greet supporters during a homecoming campaign rally Sunday in Waukesha, Wis. Justin Sullivan/Getty Images hide caption

itoggle caption Justin Sullivan/Getty Images

Rep. Paul Ryan, who has been chosen by Mitt Romney to be his running mate on the GOP ticket, greeting supporters Sunday in his home state of Wisconsin. Ryan will be in Iowa today. Saul Loeb/AFP/Getty Images hide caption

itoggle caption Saul Loeb/AFP/Getty Images

U.S. Rep. Paul Ryan, R-Wis. stands during a listening session in April 2011 in Kenosha, Wis. He is now presidential candidate Mitt Romney's running mate. Jeffrey Phelps/AP hide caption

itoggle caption Jeffrey Phelps/AP

A screen grab from "America the Beautiful" by The Agenda Project. According to PolitiFact, videos like this one used elderly actors to falsely suggest that Rep. Paul Ryan's Medicare plan would adversely affect current senior citizens. The Agenda Project/YouTube hide caption

itoggle caption The Agenda Project/YouTube