Levees, like this one in New Orleans, must be certified by the U.S. Army Corps of Engineers before appearing on federal flood maps. This change has resulted in higher flood insurance premiums in some areas. Mario Tama/Getty Images hide caption

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Sen. Mary Landrieu, D-La., has won some conservative supporters in her state, but her support for Obamacare is putting her re-election at risk. Evan Vucci/AP hide caption

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Sen. Lindsey Graham, R-S.C., questions a witness during an April 23 hearing on the use of drones on Capitol Hill in Washington. Cliff Owen/AP hide caption

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Supporters for gun rights gather outside the National Shooting Sports Foundation headquarters in Newtown, Conn., on March 28. Jessica Hill/AP hide caption

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