U.S. Senators McCain and Kyl leave the Senate Chamber for the caucus at the U.S. Capitol in Washington

U.S. Senators John McCain (R-AZ) (L) and Jon Kyl (R-AZ) leave the Senate Chamber for the caucus at the U.S. Capitol in Washington December 30, 2012. Efforts to prevent the economy from tumbling over a "fiscal cliff" stalled on Sunday as Democrats and Republicans remained at loggerheads over a deal that would prevent taxes for all Americans from rising on New Year's Day. REUTERS/Mary Calvert