I don't know how liberals will react tbh. Usually they try to work within the system, but if that should ever prove to become impossible... I haven't studied enough history to get any kind of accurate impression, but it's worth noting that nothing like it has been needed (within the USA) in the last hundred years or so, so whatever might come seems hard to predict.

I should add that Democrats are also cowards too, as are most individuals - neither side holds a monopoly on that. That's what makes this all so dangerous: if something could be accomplished behind the scenes, then 99.9999% of Americans will simply go along with the flow. Exactly like within Russia, even the thinnest vernier of respectability would be enough to forestall a large-scale conflict. So the "constitutional crisis" might take the form of a fairly bloodless (in the wider sense) coup.

Or Republicans could just keep turning the ratchet, making steady gains wherever they can, then locking in those gains and turtling, obstructing as best they can whenever they do not hold a majority, as they have been doing for decades now. In one sense that's even entirely fair - a democracy should reflect the majority will of the people - except Republicans are aware that white people are becoming in the minority now and so have been changing more and more over time who gets to be counted as "people". e.g. gerrymandering, with the stacked Supreme Court members not opposing it so now it's "legal". Though even that is becoming not enough lately thus they are having to adjust the stakes higher, possibly doing away with voting altogether (yes they are literally talking about that, hence all this discussion about Civil War). They have already been allowed to push that far, which leaves fewer options for them to move forward with short of something drastic.

The trick is that to the uninitiated, much of it sounds reasonable at first - e.g. "states rights" means that we all get to choose our own paths, and what is wrong with that, isn't that "freedom" in the truest sense of the word? The trouble is how the lie is delivered along with the truth: for one, the means by which those gains were achieved has enormous implications, which feeds into two, it was actually always a lie bc they never stop there and always push forward after people accept the first push. i.e., if only appeasement would ever actually work! However, like that famous saying "first they came for...", where even if you don't care about those first few that were come for, eventually they will come for YOU too, and if you had been paying attention then there would be no need to be shocked, shocked I tell you, shocked! Leopards eat faces off, and just bc one hasn't eaten YOUR face off, yet, doesn't mean that it never will. They tend not to change their spots, only their current targets. Like Brexit, many people in the USA won't know what's happening anytime before, during, or somehow even after it has happened.:-(

And some are even joining in with the leopards, neither realizing nor seemingly caring that they are just being saved as future meals for those who are true predators. These "facilitators", together along with the much more numerous "collaborators", collectively are bringing literal (neo-)Nazis back into power.