There are things he can do--in fact things they're actively working on right now--to interfere with and upend that process specifically. It's largely uncharted territory, so people dismissing these possibilities outright aren't on any surer footing than the rest of us. I think it's likely their efforts to a) sue and otherwise intimidate electors and SoS directly, b) convince enough Democratic electors to be bad faith electors, c) persuade Republican legislatures to appoint their own slates of electors will be unsuccessful, but their best bet, and likely the one they're banking on, is getting cases in front of Fed Soc funneled judges who are varying degrees of incompetent and grotesquely partisan and corrupt. If they can block certification here and there, get Democrats' ballots tossed a few other places, narrow the margins and delay, I'm sure they're hoping they can get a 2000-style safe harbor reprieve from the Supreme Court. Every piece is something of a long shot, but Trump has literally everything to lose.