I think the bigger problem wasn’t that Biden was going to lose a lot of voters in the middle of the spectrum to Trump. I am pretty sure Trump has had poor polling numbers among independents and moderates for a while, even when he was otherwise leading all of the overall polling, and I dont think there was much danger of there being a significant number of Biden 2020-to-Trump 2024 voters. I think the bigger problem was that Biden being on the ticket, especially after the debate disaster, had done such irreparable damage to enthusiasm and excitement on the left that it was going to significantly depress Democratic and Democratically-inclined turnout. Ever since the emergence of MAGA in our national politics, literally the only national election- general or midterm- they’ve won was aided and abetted by depressed Democratic turnout in 2016. Ever since then, MAGA has been losing elections because it’s a massive electoral loser that is repulsive to everyone who isn’t already a weirdo MAGA freak. Democrats don’t lose elections to MAGA when Democratic enthusiasm and turnout is elevated. But Biden remaining on the ticket after the debate was almost certain to cause a 2016 turnout redux.
In less than three weeks we’ve gone from the prospect of depressed Democratic turnout- and thus a probable Republican blowout- to a wave of energy, enthusiasm, excitement, fundraising, volunteerism, and new voter registration reminiscent of Obama’s first campaign- and thus a more probable-than-not Democratic victory.