Biden's constant insistence on Trump being an outlier and the GOP's fever breaking once he's gone is both baffling to me, given his personal experience with the complete opposite for eight years, and one of the biggest reasons he's not my preferred choice in the primary by far. At the same time, I would absolutely 100% with no reservations take a Biden presidency with his proposed healthcare and climate and gun control policies, and his latitude over steering the courts away from the Federalist Society's clutches, over another four years of Trump if those were the two choices in a general election. And it's insane to me that any reasonable progressive who wants anything better for this country does not see the night and day difference between the two.
I don't think this mindset really reckons with how bad Trump is, how much damage he has done so far, and how much more consequential that legacy will be if he gets another four years at it. Trump may be a symptom of a bigger disease, but that doesn't change the fact that he is a particularly catastrophic and uniquely powerful symptom. Nothing, literally absolutely nothing, that a progressive wants to see happen will happen under a second Trump term. Even worse than that, the potential for progressive change post-Trump will be eroded further under another four years of Trump. A Biden presidency may not champion all or most ideal progressive policies, but a continuing Trump presidency will totally salt the earth to prevent those progressive policies from even being able to happen under, say, a President AOC. A continuing conservative Supreme Court and a judiciary being reshaped by Trump and Leonard Leo will see to that.