I don't think so. I don't believe Biden won office by fraud, but even if he did, it would not likely be the first time. JFK in '60 is possibly one example. It's not good, but we survived. I think it's naive to assume there haven't been other frauds in the past two-and-a-half Cs. We manage. We move on. Problem is Trump can't.
As a thought experiment, can you imagine Trump, under any circumstances, conceding? Accepting the loss & moving on?
Because I certainly can't.