The SCOTUS could be stopped if there’s enough popular support to ignore it or override it through legislative or constitutional means. Little Nemo mentioned amendments - that’s arguably the most satisfying and appealing remedy. But courts depend on legitimacy. The threat of a court packing is an idle threat most of the time, but not if the courts continuously vote down legislation that the public overwhelmingly supports, and I think you saw John Roberts moderate himself on Obamacare for that very reason.
D’OH !
Thank you to both @Little_Nemo and @asahi. I had forgotten the Amendment recourse.
While I did take Civics in school, it may have been before the outgoing FLOTUS (!) was born 
The fact McConnell has already said that any election dispute would be solved by the courts heavily implies that if the Courts rule Biden is President McConnell will have the rest of the Senate Republicans fall in line and accept the results.
There’s also the fact that the Senate Republicans all openly refused to pass another stimulus bill despite Trump wanting to since he assumed another big check would get people to vote for him. You would think if they were this down on the Trump kool-aid they’d have passed that second stimulus bill no questions asked especially since Trump’s re-election was at stake.
My personal opinion is that Roberts has moved away from the right in an effort to keep himself relevant. There was a period when everyone assumed that four justices would vote one way, four justices would vote the other way, and the final outcome would be whichever way Anthony Kennedy voted. People were saying that the law ended up being whatever Kennedy decided.
I feel Roberts was annoyed at how he was taken for granted. So he started joining rulings that weren’t in lockstep with the other conservatives. It was his way of shaking up the balance in the court and taking control.
One more option for the specific instance of a presidential election: states are allowed to choose for themselves how to select electors. Theoretically, state legislatures could pass laws letting them choose the electors without a vote of the people, bypassing court rulings on elections altogether. That would be unpopular and nigh-impossible, probably triggering additional lawsuits, but it’s an option.
The SCOTUS can make any ruling it likes and you could see a 6-3 or 5-4 decision in Trump’s favour on virtually any issue.
Not so theoretical. Originally, that’s how a lot of states chose their electors (and senators were also chosen by the legislatures.) Most states switched to selecting them by popular vote in the early 1800s, but the legislature selected them in South Carolina up until 1860.
I took that as theoretical as in it would be a nuclear option which could likely backfire.
I agree it is politically impossible now. I was just mentioning it’s not completely without precedent (even if not within the past 180 years).
You left out what I suspect would be the most likely option: impeach every justice who somehow found a way to contort the first amendment or any other part of the Constitution into a “King for Life” clause, replace as needed/desired, and invite the new court to reconsider.
But of course if we’re in bonkers land and somehow the Senate won’t do that, then I don’t think any other option can be entertained as I’d first need to be more familiar with what else has gone awry in this hypothetical alternate reality in which the court both somehow rules POTUS can be king for life and more than a third of even the most conservative Senators from this reality are cool with that. Because while there would be other recourses (as you list) beyond that, if we’re playing fast and loose with reality, obviously anything is possible.
But beyond “Step 1. Impeach every justice who so ruled,” I don’t see the point in continuing down that hypothetical myself.
As to the OP, keep in mind the court’s ability to interfere with results at this time would have to be limited to individual states and their processes. I see no mechanism for them to set aside the results of every state-level election in one fell swoop. If they could, well, again, I think that puts us into a fantasy realm that is too far off from our own reality to contemplate at this time.
The last time this option was used was 1876 and it was under special circumstances. Colorado had just been admitted as a state on August 1 and they were not able to set up a voting system for the presidential election on November 7. So the new state legislature chose Colorado’s three Electors. It was not the most controversial aspect of that election.
The Florida legislature chose that state’s Electors in 1868 because Florida was still under reconstruction. The Louisiana and Tennessee legislatures chose Electors in 1864 because things were … difficult.
South Carolina was the last state to have the legislature choose Electors in normal circumstances in the 1860 election. South Carolina was definitely the hold-out on this; the second-to-the-last state to choose Electors by the legislature was Delaware which stopped doing it after 1828.
FWIW, the National Popular Vote Interstate Compact is premised on the same idea. That state governments are the ultimate arbiter of which electors (for which candidate) get selected. The idea being that if states compromising more than half the electors agree to commit all their electors for whichever candidate wins the popular vote, they can effectively undercut the electoral college without need for the more rigorous constitutional amendment process.
I’ve thought about this some more.
Up until five years ago, I would have agreed with the assessment that it would be “impossible” but I think it’s “highly unlikely.” Unfortunately, I don’t know if anything could be ruled out these days.
In the America I grew up and lived in, any party which did that would have severely punished at the ballot box. In this hyper partisan environment, I’m not so sure anymore.