Paul Ryan addresses the Family Research Council Action Values Voter Summit in Washington, D.C., on Friday. Mandel Ngan/AFP/Getty Images hide caption

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Towns near the Ohio River, including Steubenville, seen here in 2009, are home to many undecided voters. One of them, Brian Snider, says, "This is pretty much a ghost town." Rick Gershon/Getty Images hide caption

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Senate Majority Leader Harry Reid, D-Nev. speaks to the media at the Capitol in March. T.J. Kirkpatrick/Getty Images hide caption

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Ted Cruz, Republican candidate for the U.S. Senate, speaks at a rally organized by the Tea Party Express in San Antonio in May. Hernan Rozemberg/AP hide caption

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Former Arkansas Gov. Mike Huckabee delivers remarks to the Conservative Political Action Conference in February in Washington, D.C. Chip Somodevilla/Getty Images hide caption

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Republican presidential candidate Mitt Romney makes a pie shell with store owner Linda Hundt during a campaign stop Tuesday in DeWitt, Mich. Joe Raedle/Getty Images hide caption

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Iowans attend a marriage rally sponsored by The Family Leader on Tuesday at the Statehouse in Des Moines. The head of the organization says President Obama's endorsement of gay marriage could cost him the election. Charlie Neibergall/AP hide caption

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Vice President Biden defends the administration's foreign policy --€” and questions Mitt Romney's ideas — on Thursday at New York University. Lucas Jackson/Reuters/Landov hide caption

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Republican presidential candidate and former Massachusetts Gov. Mitt Romney speaks at a campaign rally in Tempe, Ariz., on Friday. Jae C. Hong/AP hide caption

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Courting Tea Party voters in Philadelphia on Monday night, Mitt Romney speaks next to a large statue of Benjamin Franklin at the Franklin Institute. Tim Shaffer/Reuters/Landov hide caption

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Rick Santorum won the Louisiana Republican presidential primary Saturday, beating front-runner Mitt Romney in the race to challenge President Obama. Jae C. Hong/AP hide caption

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A screen shot of President Obama from the trailer for his campaign's movie The Road We've Traveled. BarackObama.com/YouTube hide caption

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Peoria, Ill., as seen from across the Illinois River. Jeff Haynes/Reuters /Landov hide caption

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