Even an R+1 environment (which the WA primary suggested) results in the Republicans winning a solid margin in the House and most of the toss-up Senate seats. That's a 5.5-point swing from 2020.
If it's a R+1 environment, Democrats will probably hold all of their Senate seats and flip PA.
That would suggest very strong Democratic trends in a number of states; PA/AZ/GA all
should be gone at ~D+3, and while there's lots of evidence that GA has a very strong Democratic trend and might well defy the wave this time around, the evidence of this for AZ or PA is much more lacking. (At D+1 NV should be flipping as well).
It would be modestly surprising but not impossible if Democrats won
one of PA/AZ/GA/NV at R+1, but 2+ would suggest a set of very well-run campaigns, and 4/4 would be insane. I don't think there's much reason to think that'll happen; I've said since this summer that an underrated possible outcome is an outright Democratic victory in the GCB (like D+3) which is still accompanied by Republicans sweeping competitive Senate and House races.
