Sen. Arlen Specter, center, buttons his jacket as he walks with his wife Joan and fellow Senators Byron Dorgan (D-ND), third from right, and Orin Hatch (R-Utah), after Specter announced he was switching political parties, in Washington, Tuesday, April 28, 2009. Sepcter said on Tuesday he would switch to the Democratic party, presenting Democrats with a possible 60th vote and the power to break Senate filibusters as they try to advance the Obama administration's new agenda. (Doug Mills/The New York Times) (Doug Mills/The New York Times)