“It’s like watching someone you love die of a wasting disease,” she said, speaking of our country. “Each day, you still have that little hope no matter what happens, you’re always going to have that little hope that everything’s going to turn out O.K., but every day it seems like we get hit by something else.” Some mornings, she said, it’s hard to get out of bed. “It doesn’t feel like depression,” she said. “It really does feel more like grief.”

Obviously, this is hardly the first time that America has failed to live up to its ideals. But the ideals themselves used to be a nearly universal lodestar. The civil rights movement, and freedom movements that came after it, succeeded because the country could be shamed by the distance between its democratic promises and its reality. That is no longer true.

Democrats and anti-Trump Republicans are often incredulous seeing the party of Ronald Reagan allied with Vladimir Putin’s Russia, but the truth is, there’s no reason they should be in conflict. The enmity between America and Russia was ideological. First it was liberal democracy versus communism. Then it was liberal democracy versus authoritarian kleptocracy.

But Trump’s political movement is pro-authoritarian and pro-oligarch. It has no interest in preserving pluralism, free and fair elections or any version of the rule of law that applies to the powerful as well as the powerless. It’s contemptuous of the notion of America as a lofty idea rather than a blood-and-soil nation. Russia, which has long wanted to prove that liberal democracy is a hypocritical sham, is the natural friend of the Trumpist Republican Party, just as it’s an ally and benefactor of the far right Rassemblement National in France and the Lega Nord in Italy.

The nemeses of the Trumpist movement are liberals — in both the classical and American sense of the world — not America’s traditional geopolitical foes. This is something new in our lifetime. Despite right-wing persecution fantasies about Barack Obama, we’ve never before had a president who treats half the country like enemies, subjecting them to an unending barrage of dehumanization and hostile propaganda. Opponents in a liberal political system share at least some overlapping language. They have some shared values to orient debates. With those things gone, words lose their meaning and political exchange becomes impossible and irrelevant.

Thus we have a total breakdown in epistemological solidarity. In the impeachment committee hearings, Republicans insist with straight faces that Trump was deeply concerned about corruption in Ukraine. Republican senators like Ted Cruz of Texas, who is smart enough to know better, repeat Russian propaganda accusing Ukraine of interfering in the 2016 election. The Department of Justice’s inspector general’s report refutes years of Republican deep state conspiracy theories about an F.B.I. plot to subvert Trump’s campaign, and it makes no difference whatsoever to the promoters of those theories, who pronounce themselves totally vindicated.