That's a different front, though.
Even if it's a response to those things, the level of "don't cooperate even on issues where you agree/used to agree" has not been the same between parties.
> when half the populations entire political identity is “whatever we think will make the other side angry”?
The idea here is that Republicans are somehow out to spite the Democrats more than vice versa, and I frankly don't see it. Both sides believe the other to be acting in bad faith, and honestly from my perspective it certainly looks like both sides are acting in bad faith.
We've had more than our fair share of close calls to government shutdowns the past four years, but let's not forget that Congress actually did fail to fund the government twice during Trump's presidency. The current Congress flirts with the line but has always ended up actually finding something that can pass.
Only if you're looking at it from the Democratic perspective. From the Republican side they look at Democratic policies from the last decade and see a group that suddenly decided to throw all previous social norms out the window and upend social order. They see themselves as reacting to that change in the Democratic Party.
I think the truth is that both parties simultaneously escalated, but that perspective usually gets shouted down pretty hard by both sides who each really want to perceive themselves as the consistent one.