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

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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

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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

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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

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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

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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

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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

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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

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