Stocks shook off their post-election slump Monday, in part because of optimism that the president and Congress will reach a compromise on the nation's budget by the end of the year. If they don't, there will be automatic tax increases and huge cuts in federal spending -- that so-called fiscal cliff. It's a time bomb, according to Lloyd Blankfein, chairman and CEO of Goldman Sachs, and one of the world's most influential bankers. His message to Washington? Make a deal.