US Democratic presidential candidate Senator Barack Obama (D-IL) speaks at his "Super Tuesday" primary election night rally in Chicago, Illinois, February 5, 2008. Twenty-four of the 50 states are holding nominating contests for one or both parties on "Super Tuesday" for a huge haul of delegates to this summer's conventions that will choose the candidates for the November presidential election. REUTERS/Frank Polich (UNITED STATES) US PRESIDENTIAL ELECTION CAMPAIGN 2008 (USA)