Guests stand after a Rand Paul speech at the Conservative Political Action Conference (CPAC) in Rosemont, Ill. Conservatives celebrated Tuesday's victory in Wisconsin's recall election. Scott Olson/Getty Images hide caption

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Wisconsin Republican Gov. Scott Walker (right) celebrates his win over Democratic challenger Tom Barrett at Tuesday night's victory party in Waukesha, Wis. Morry Gash/AP hide caption

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Supporters listen to Republican presidential candidate Rick Santorum at The Ravine in Bellevue, Wis., on March 24. Some voters in the state are complaining about a barrage of negative ads in advance of Tuesday's primary. Darren Hauck /Reuters /Landov hide caption

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Volunteers at the Wisconsin Democratic Party's recall office in Waukesha entered names from petitions to recall Gov. Scott Walker into their voter databases on March 20. Liz Halloran/NPR hide caption

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