I spend a big chunk of 2016 warning that the polls were systematically under-stating the impact of polite white racists in the midwest who say they're "undecided" right up until they swing GOP, like always.
Same thing in 2020 - Biden only barely, barely won, and the coup attempt was only thwarted by the fact senior GOP folks and the Supreme Court thought it was giving the deep game away if they overturned an election where the GOP outperformed.
The hard right is absolutely honest about their goals: making the Constitution a document powering a self-serving Evangelical nationalism.
They're not stopping because they see the alternative as oblivion - and because the opposition is in thrall to wealthy Northeasterners bound and determined to pretend they're not racist because the Union fought the Civil War (and abandoned Reconsturcion when it became too hard).
Bottom line - only half of Biden's support was really pro-Biden. The GOP has made it legal for state legislatures to overturn the popular vote in Presidential elections and there's no sign the Supreme Court is planning to knock this back.
Most critical of all, the GOP boosted its appeal to non-white voters, especially ones without a degree. Not enough to win these groups, but a clear warning sign that something is seriously wrong with the Democratic Party's ability to appeal to its theoretical base.
In a basically tied game where every inch matters, this is deadly.
But it's all but impossible to get through to the Dem's leadership. Their coalition is only held together by grace of not being completely anti-democracy.
I see no way this doesn't end horribly. In the best case, an anti-Trump 3rd party splits off and takes some Western Red states like Utah out of the GOP column. The election is decided in Congress, where one has to hope a Dem-Third Party alliance forms to keep Trump out of office.