I don’t think you’re correct about this.
I live in the bluest part of a very blue state. Most of the people I know are dyed-in-the-wool Democrats - mostly so out of sheer habit. They aren’t necessarily ‘anti-Trump’ but ‘anti-Republican’; that’s how they’re conditioned.
On the other hand, they can see very well what their lives are like under Biden, as opposed to how they were under Trump. I’m sure they see how poorly Biden did tonight, too.
If Biden is replaced, most will probably still vote Dem; but I don’t think they’ll resent it much if Biden IS replaced. He’s not doing anything for them. They tend to be Party people, not Candidate people.
That is my area as well—not my town—but the nearest suburbs.
Our best chance for their votes is to keep Biden on the ticket and let him deteriorate further between now and November.
Some of them might hold their nose and vote for President Trump if Biden was in bad enough shape.
If Biden was replaced they would vote party as you say.
But what you have just said would not generate impetus to replace him. Those samples aren’t going to change after the debate.
They will still vote for the Dem.
This is my point. It’s very hard to move the needle and if it doesn’t move then they won’t replace him. Remember, an EV loss of the presidency may not cost them many seats in Congress. Split ballots from Independents is a very likely thing. So if their seats are not at risk, their sense of urgency to replace Biden diminishes.
This is the Swamp we’re talking about. They don’t care much about policy.