Volunteer fire fighter Joe Crawford fights a wildfire in Graford, Texas, in September, when wildfires swept through parts of Texas and Oklahoma. Tom Pennington/Getty Images hide caption

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Newt Gingrich speaks Monday at Global Security Services in Davenport, Iowa. Despite falling poll numbers, Gingrich says he will avoid negative campaigning. Chris Carlson/Associated Press hide caption

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Republican presidential candidate Ron Paul spoke at a town hall meeting at the Ericson Public Library in Boone, Iowa, on Thursday before a university rally. Kevork Djansezian/Getty Images hide caption

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George Allen, a former U.S. senator and Virginia governor, speaks to employees of an auto parts manufacturing plant near Roanoke, Va., on Oct. 5. Allen is trying to recapture the Senate seat he lost in 2006. Stephanie Klein-Davis/AP hide caption

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A Predator drone takes off on a U.S. Customs Border Protection mission from Fort Huachuca, Ariz. Ross D. Franklin/AP hide caption

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This video frame grab provided by the Mitt Romney presidential campaign shows a scene from an ad called "Believe in America" that is running in New Hampshire. Romney Presidential Campaign/AP hide caption

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In September 1994, then-House Minority Whip Newt Gingrich addressed Republican congressional candidates on Capitol Hill during a rally where they pledged a new "Contract with America." Months later, Republicans gained control of both houses of Congress for the first time in decades, and Gingrich became speaker of the House. John Duricka/AP hide caption

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Gingrich talks to a breakfast crowd during a campaign stop at the Circle Restaurant in Epsom, N.H., on Friday. A new CBS poll of Republican primary voters finds him tied for second place with Mitt Romney, behind Herman Cain. Jim Cole/AP hide caption

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Passengers wait to clear security next to the newly opened pre-check lane at Miami International Airport. The airport is one of four that is allowing frequent fliers to use a special security line where they can keep their shoes on and their laptops in their bags. Joe Raedle/Getty Images hide caption

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