I just thought of another possible scenario.

Donald Trump is initially declared the winner of the election. However, his win is contested and then overturned because of election fraud; it could be false or real claims; it doesn't really matter.

As mentioned in the post, no federal election has been overturned because of fraud. However, Donald Trump is a man of many firsts. If the election is overturned against him, it will be even more chaotic than if it was stolen from him because of fraud. It would also be ironic considering the claims of election fraud have been mostly coming from his side.