The feeling is that now everything will "go back to normal". Back to establishment politics. But there's 70 million people who are still clearly frustrated with that and made this a surprisingly close election, but these people will now be ignored. Most of the media completely ignores this reality. If you only watched the media (which is centered in New York and LA) you'd be astonished over the Trump support, it just doesn't make sense to these people. It will be interesting how the populist movements on the right and left in the US go from here, and what happens in 4 years.
Trump obviously wasn't the right guy to fix this problem, but the problems still remain.
I don't know where you get your figure of 70 million from, but I have no better number to offer. However, let's try to break it down:
Suppose that half of Trump's supporters are those ordinary Americans who voted for him in 2016 out of desperation.
And suppose that at least half of Biden's support are the same kind of people who are looking for relief from the failed system in the same way but are choosing a different path to get there.
Is that how you arrive at the 70 million?
Then there are the other halves of both camps who are content with the status quo because they have good paying jobs, healthcare, and other social benefits.
I could go into more detail but this is to first of all offer an understanding of what you're meaning.
And so I see a return to the same old politics that suit the situation. That is, unless they finally come to the realization that they're not the world's only sane democracy and the rest of the world's democracies aren't 'commies'. That's the key! Threre's a huge faction that have kept the people believing that there's a commie under every bed and all that needs to happen for them to come out of hiding is having the people accept a better system of capitalism with social responsibility.
Is this the breakpoint that will allow that to happen? I see few indications of any understanding of that by Americans.