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

itoggle caption Jae C. Hong/AP