For a liberal coup to happen, the Democrats are going to need an opening to seize power from a disastrous Republican administration that makes Trump’s look like an age of Camelot. Given our politics resembles a mix of Egypt and Brazil, that requires a first overthrow first, like with the Morsi government/Operation Coupwash Carwash.
I seriously doubt it man, if we get to that stage I don’t see us getting over that cleanly and not already being in a state of civil war.
A Civil War that takes place in the world's most powerful nation will eventually envelop the most of the world. A coup at home might be a bigger existential threat to "civilization" than the current war in Ukraine.
I highly doubt many will want to get involved in our domestic quagmire in the first place, and that includes most of NATO, but even still I wouldn’t be too concerned of the final outcome given that if Syria could survive I can bet we will too.
And though I am now more at ease that Russia would still be beaten back by the EU, I am not so sure that Japan, Taiwan, Australia, and Korea could effectively stand up against the PRC. The United States collapsing would be the international politics of the Chicxulub asteroid. Maybe the damage would be minimized if one party quickly stabilized things and the other took to the hills, bush, and trees.