It all comes down to this. And I fear that the US is in short supply of it.
President Donald Trump said that it will take a “brave” judge or legislature to take action to overturn the results of the election.
No doubt. Given the climate, I can't imagine that a judge of any court, including the SCOTUS, would want to be known as the person who 'awarded' Trump the election. It could even put their lives in danger. At best, I think SCOTUS judges might we willing - on presentation of ironclad evidence - to rule that the vote count in some states was so marred by irregularities that it is not possible to say that EITHER candidate won those states.
In this scenario, Biden's EC total might fall below 270, and the process would then proceed, as per the 12th amendment, to each state getting one vote and voting on the basis of which party has a majority of members of congress. Across 50 states, that would mean Trump gets elected, and it would be constitutional. Of course, the Dems would try to hold up the process through the courts etc.
If we're positing a hidden higher hand behind all this, then it makes sense to consider what REALLY concerns those types. It's pretty clear (look at 'covid') that the agenda of those people is (and has been for a long time) population control. We know that the rise of populism in Europe and the US over the past few years received immediate and vicious condemnation by the 'established authorities', mainly because it's message of "power in and to the people" poses a direct threat to the 'deep state's' brand of elite authoritarianism and absolute control from above.
The US is a big country and still has the power to set standards in various fields around the world. For that reason, it, above all other countries perhaps, must be kept in line, and the conservative mindset appears to be a serious thorn in the side of the 'deep state' types in that respect.
We might say that the obvious way to deal with Trump and his populism is to deny him the election, but think about it this way. Biden becomes president, Trump moves into "private life", but not really. He remains the unofficial head of the GOP and is still looked up to by 100 million Americans (or more). He tweets every day to the faithful, acting very much like the President of a parallel govt. (at least in terms of having the eyes, ears and hearts of so many Americans). Every attempt Biden makes to convince the population of some new policy or rule, Trump opposes it, and tens of millions listen to him and look to him, not Biden, for what their perspective should be. Even worse, during Biden's term, Trump starts a new TV network that becomes very popular and continually counters the official narrative. He also starts to build his campaign for another run at POTUS in 2024, or grooms his replacement. By ousting Trump in a rigged election, his enemies might realize that they would simply be empowering him to consolidate and grow his popularity and come back even stronger.
So what's the alternative?
So the Dems challenge Trump being nominated POTUS by the states, and that drags on, but through it all, Trump is loudly derided as an illegitimate president and dictator. Massive riots, violence and general chaos and disorder in public and political life define the first few months, plus martial law imposed by Trump, convincing his detractors that he really is a dictator. It could get so bad that, when the dust finally settles, the general consensus might be that "this must never happen again" with the finger of blame for all the chaos pointed squarely as Trump, Trumpism and populism. The 'deep state's' desired end result being that populism gets a VERY bad name, and Trump and Trumpism is sidelined forever more, or so they hope.
If this were to play out in this way (or similar), in order to maximize the outrage, screams of 'not my president' and social chaos, it requires that evidence of election fraud is left for Trump's legal team to find and *ultimately* use to change the result, ideally at the last minute, when the confidence of anti-Trumpers that the 'nightmare of Trump' is finally gone is at its highest, so that the shock and outrage will be the greatest.
Anyway, this is just me fleshing out a possible scenario and the possible rationale or motivations for it.