Democratic presidential candidates U.S. Senator Obama and U.S. Senator Clinton attend a political debate at Drexel University in Philadelphia

 
Democratic presidential candidates U.S. Senator Obama and U.S. Senator Clinton attend a political debate at Drexel University in Philadelphia
Democratic presidential candidates U.S. Senator Barack Obama (D-IL) (R) and U.S. Senator Hillary Clinton (D-NY) attend a political debate at Drexel University in Philadelphia, Pennsylvania, October 30, 2007. REUTERS/Larry Downing (UNITED STATES)