Republican presidential candidate US Senator John McCain (R-AZ) and his wife Cindy greet supporters at his "Super Tuesday" rally in Phoenix, Arizona, 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/Shaun Best (UNITED STATES) US PRESIDENTIAL ELECTION CAMPAIGN 2008 (USA)