President Bill Clinton’s quiet dinner with political consultant James Carville at Gabriel’s on West 60th Street Monday night was almost disrupted by an impromptu visit from George W. Bush. “Bush screeched up in a motorcade, walked into the restaurant, came into the bar area, then turned around and left. We don’t know if it was because Clinton was there,” said a source. As he left, Bush quipped to the staff: “I am going home to the promised land.” Clinton and Bush had earlier spoken at a private panel hosted by Wealth Management Americas, an arm of UBS, at Lincoln Center.