If he thinks he’s going to lose, of course he would. Everything in his past and present tells us that he will do literally anything in his power to avoid being seen as a loser. Nothing in the Constitution, nothing in a statute book, and no norm of any kind is sacred to him–only his self-image as the ultimate winner. He would do it in a heartbeat.
The real question is whether America would let him get away with it. Would Mitch McConnell and Lindsey Graham try to stop him? Would GOP officeholders all over the country take a stand for liberal democracy regardless of their immediate self-interest? What about the armed forces? Has the corruption spread so far that, like the virus, it can’t be stopped?
I regret to say that I don’t know the answer to that question. Fortunately, the man is so delusional about his popularity that defeat would probably come as a shock regardless of what the polls say, so the issue will most likely never arise.