@Lazarou I suspect they don't have any particular plan that can improve it.
There are several factors against improvement:
All metrics (that aren't "American isolationism and racism") during the Biden administration are objectively better (and the ones that aren't would not have been better under Trump; for example, there's no reason to believe Trump wouldn't toady up to Netanyahu. He is known to respect strongmen). Voters don't care. Voters want solutions, not incremental improvement. And "solutions" look a lot more like "Getting my way right now" than "Figuring out how to co-pilot a country with people who want the opposite of what I want."
For as risky as running Biden is, they know that running someone else is historically riskier. Parties, at their core, have to exhibit strength of conviction or they aren't parties. Failing to back the guy currently running the executive sends the signal that maybe they shouldn't have backed him four years ago. I personally think that's dumb but it is the X-factor in all of this---Americans generally expect the party to back a try for a two-term President instead of a one-term followed by someone else entirely.
For as awful as he polls, he polls better than the other candidates the Dems think they can field. Ultimately, a President isn't decided just on the people in his party; he also has to pull votes from people in the other party. So the Dems are always going to field someone closer to conservative viewpoints than left-wingers would choose.
There are some problems parties are the wrong tool to solve.
All of that having been said: I do share your concern that their calculus is off and they really aren't thinking about how many young people are checked out. But that's the devil they don't know, so they'd be rolling some huge dice to make a guess at what that demographic wants (their signal on them is weak because they don't engage as much in traditional political channels so they aren't showing up on the signal pathways the Dems can see most easily). And if those dice come up wrong, we get a fascist. Dems can generally be trusted to make the play they perceive to be safest; they don't like rolling dice.
I think the real issue is that Biden is a terrible choice but I also can't suggest a better choice. Not one I seriously think more than half of American electors (not voters; states distort "one person, one vote") might vote for.
alexanderhay