Republican presidential candidate, New Jersey Gov. Chris Christie points toward Republican presidential candidate, Sen. Marco Rubio at the other end of th stage as Republican presidential candidate, retired neurosurgeon Ben Carson looks on during a Republican presidential primary debate hosted by ABC News at the St. Anselm College on Saturday in Manchester, N.H. David Goldman/AP hide caption

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Former Utah Gov. Jon Huntsman, former Massachusetts Gov. Mitt Romney, former House Speaker Newt Gingrich and Texas Gov. Rick Perry (left to right) take their positions after a break in a debate in Manchester, N.H., Saturday. Elise Amendola/AP hide caption

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On the day he revised his tax plan to 9-0-9, Republican presidential candidate Herman Cain signs a supporter's "999" sign after unveiling his "Opportunity Zone" economic plan in front of the Michigan Central Station, an abandoned train depot in Detroit.

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Herman Cain speaks prior to Florida's straw poll at the Orange County Convention Center on Saturday in Orlando. Cain was a clear winner in the non-binding poll. Mark Wilson/Getty Images hide caption

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Republican presidential candidate former Massachusetts Gov. Mitt Romney, right, makes a point as Texas Gov. Rick Perry listens, during a debate in Orlando, Fla. Phelan M. Ebenhack/AP hide caption

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Former Massachusetts Gov Mitt Romney (left) and Texas Gov. Rick Perry during Monday's debate in Tampa. Win McNamee/Getty Images hide caption

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