The simple answer here has always been that the GOP would confirm someone, because it's worth an awful lot to them, and also that they'll pay a price for doing so, because it's worth paying a price for something that's worth a lot to you. https://twitter.com/NateSilver538/status/1307438722317680645

By paying a price ... the polling suggests this is an unpopular move, perhaps verging on *very* unpopular depending on which poll you look at. So, it's likely to make it harder (though far from impossible) for the GOP to hold the Senate.

The other question if whether the GOP pushed Dems past some tipping point where they're more willing to take severe retaliatory actions (expanding court, adding states) and/or can do so without triggering as much of a public backlash.

And the answer is ... maybe! We'll see. But for Dems to take those actions likely requires a fairly emphatic victory (say, 52+ Senate seats + the Presidency), the odds of which are <50% even though Democrats are favored to take the Senate (a lot of their wins are narrow).