Sure
If there were actually more than a handful of these people. I don't think there is.
I don't think this is true either! Obama's "elections have consequences" wasn't really followed by the "mandate" behavior that the GOP claims and uses to push through stuff even when that mandate is less than half the vote. (Sure Reagan eventually captures the Anderson vote
in '84...)
I think there are a lot of former Republicans who don't feel comfortable in the Trump party. If I had to guess, I would say Trump Party is about 25%, with another 10% that are never-Dems. I would guess Dems are about 40%. So, that leaves ~25% of people who will vote based on how they feel in any given election. Sure some (many?) have leans - but I don't think those are insurmountable.
The polling is suggesting close races in places where they're shouldn't be close races. That suggests, to me, there is a groundswell of support for "Not Trump" - and most of that movement is coming from the 25%,
Lets consider that the Trump Party rushes through a SC justice. I think the Trump party will be very happy, but less enticed to get to the polls in November (or sooner). That opens the door to a real swing via turnout. Given that about 50% of the people vote - if that drops on one side, and goes up on the other side - that has an over-sized influence on the election. That
could lead to the kind of landslide blowout that gives everyone a false sense of the state of the nation. But, it would embolden Democrats to enact their agenda. (It might be overconfidence - but it would be there).
So, what does that mean?
1. Legislation gets pushed through that deals with thorny issues. Abortion legislation would be at the top of the list - and I think the Dem, right to choice position is shared by a majority of Americans, so this won't cause heartache in the heartland. Yes, Mississippi and Alabama will be angry, but that's not a political hot spot.
2. Statehood for DC and Puerto Rico. Both of these can be couched in terms of providing better representation for a lot of Americans who are underrepresented right now. I am also in favor of PR getting statehood just so they can deal with their own financial crisis with the same tools given to other states (but not currently permitted by PR).
3. Judicial Reform - many will call this court packing - but realistically, we should be at 13 Justices - one for each Judicial Circuit, and perhaps its time to get some Jurists from the West Coast, and Mid West on the bench. I would also not be opposed to looking at the 9th Circuit and determining if that should be broken into two circuits.
It certainly takes some bit of follow-through - but with the audacious moves by the GOP fresh in their minds - I think the Dems will be up for bold action, rather than business as usual. You will also have some populists agitators keeping pressure on the Dem leadership to make these kind of changes.