Here's what I think happened.
Trump did to Democrats what Newt Gingrich did to Republicans. Created a high-propensity voting base who is no longer going to stay home during Democrat midterms. Remember, far more Republicans showed up in 2006 and 2018 than Democrats did in 2010 and 2014.
Do you expect that today's Democrats will be more energized to vote in 2022 than during Obama's years?
I think Trump turned out a lot of apolitical people who got swiped into Trump mania and QAnon. Without him, they won’t show up.