Hie thee to 538’s House and Senate forecasts.
Page down a few pages until you find the trend lines (“How the forecast has changed”). Note how both lines show pro-Republican movement beginning about October 1st. Notice how the last day or two show the lines headed back toward Team Blue.
Kavanaugh energized the people who like bullies. Now that the bully is confirmed, Trump is not able to keep them energized.
The survivors, though, have a lifetime of trauma to work out, and their rage is building, not dissipating.
Hypothesis: Kavanaugh has cost the Republican Party a significant share of college educated white women forever. That’s a voting bloc of, I dunno, 13% of the electorate, and a chunk of 5% or 10% of that 13% is gone. Call it 1% of the national vote just shifted from “swing” to “Democrat”. Just guessing, but I think that’s what we’re seeing.