Is trump making a fool of himself and bringing reproach on the USA system of democracy ?
1) Trump really believes he can get this election result overturned, either by delaying it until it goes to the House and he is determined winner or by a final decision of "his" SCOTUS ruling to throw out enough late ballots to give him the win.
2) He's just rallying his base to keep donations coming in and will at some point concede and then declare his candidacy for 2024, which will keep many other potential GOP candidates out of the race.