Put a lid on it - Donald E. Westlake

Francis Xavier Meehan (Meehan to his friends, 'Halt!' to the cops) has ten thousand rules to live by, but only one way to make a living: stealing. Then a man in a checked jacket from Washington comes to meet Meehan in the Manhattan Correctional Center with an offer Meehan cannot refuse. For somewhere out there is an October Surprise that may dethrone the sitting president of the United States. The Washington man wants Meehan to steal the incriminating evidence and keep the president's secret in the dark. What Meehan gets out of the deal is his freedom - and maybe a little something on the side. What the president gets is another term in the White House - instead of jail. Yet on the plane ride down to meet more guys from Washington (but with better suits), the well-thought-out-plan begins to unravel. The problem Meehan faces is that no one in Washington can keep a lip buttoned - and a bunch of politicos, spies and thugs are leaking trouble this way. Suddenly it seems that Meehan's mission is about to go the way of Watergate. There's only one difference: This time they chose the right guy for the job. Hail to the thief!