Here's an interesting article, something I've been talking about a lot. That those voters who disliked both candidates, that those who voted for the candidate they least wanted to lose, not win which was Trump are now choosing Biden. One also has to remember that 9 million voters in 2016 refused to choose between Hillary Clinton and Trump, their dislike for both was that high they voted for a third party candidate that they knew had no chance of winning. Such was the amount of dislike of both major party candidates.
"For Some Reluctant Trump Voters, Coronavirus Was The Last Straw"
For the record, I was one of the 9 million folks who voted against both Trump and Clinton. Both major party candidates disgusted me to no end. It was like both major parties went searching for the candidates that would disgust most Americans, candidates Americans would dislike and not want to become their next president. They certainly succeeded in 2016.
Don't forget the Libertarians, who did their best to compete in kind.
2016 proved again the truth of Greek Tragedy, wherein the failings of each actor proved their downfall, even the actor who seemingly "won", but who seems likely now to receive its comeuppance... due to those same failings.