If the blue wave occurs, he will resign within a month or two. The specter of possible impeachment and 24/7 investigations will weigh heavy on him, his approval rating will continue to fall. Like a kid who can't hit when up to bat, he'll take his ball and go home. Of course he'll exclaim he won.
Pardoning Dirty Manny doesn't wipe away his convictions. He was also convicted of tax evasion, so back taxes and fines are in order, it wouldn't relieve him of that obligation. He robbed from the American taxpayer. Either way, Dirty Manny is bankrupted. Morally, ethically and monetarily.