The House impeachment probe has reached a point where continuing to defend President Donald Trump requires a prodigious capacity for denial or self-delusion.

Sen. Lindsey Graham, Trump’s denialist in chief, summed up the situation on Tuesday when asked about Gordon Sondland’s revision to his testimony before the committees three weeks earlier. Originally, the hotel tycoon–turned–ambassador couldn’t remember much about a quid pro quo. But now that his memory had been refreshed by other witnesses’ depositions (which may have incited worries of a perjury prosecution), Sondland said this week that yes, come to think of it, the president did hinge the resumption of military aid to Ukraine on Ukraine’s willingness to investigate—and make a public statement about—the corruption of Joe Biden and his son.

Graham, chairman of the Senate Judiciary Committee, replied that he hadn’t read the testimony of any of the witnesses, a roster that includes not just Sondland, a major donor to Trump, but also some esteemed career diplomats. “I’ve written the whole process off,” Graham said. “I think this is a bunch of B.S.”

Just two weeks earlier, Graham said in an interview, “If you could show me that, you know, Trump actually was engaging in a quid pro quo, outside the phone call [with Ukrainian President Volodymyr Zelensky], that would be very disturbing.”

Now Sondland has done precisely that—and suddenly, it’s not disturbing at all. Or, rather, it’s so disturbing that Graham has blocked it from his mind—pretended that it doesn’t exist.

Similarly, in late September—around the time reports of Trump’s July 25 phone call with Zelensky began circulating—Steve Doocy, co-host of Trump’s favorite TV show, Fox & Friends, allowed, “If the president said, ‘I’ll give you the money, but you’ve got to investigate Joe Biden,’ that’d be off-the-rails wrong.”

Now that the evidence has shown the president pretty much said that, the rails, in the eyes of the many Trump friends at Fox, seem as right as rain.

Republicans risk turning gaslighting into a permanent political condition.

Trump’s lines of defense have been crumbling under each wave of new facts. First, his phone call with Zelensky was said to be “perfect.” (Trump continues to make this claim, though he is nearly alone in doing so.) Then, yes, Trump pressured Zelensky, but there was no quid pro quo. Then, OK, there was a quid pro quo, but diplomacy is all about quid pro quos. Then, well, all right, this quid pro quo involved pressuring a foreign power to defame a possible rival in an American presidential election, and that doesn’t look good, but it’s not an impeachable offense. Finally, at our present moment, some Republicans realize that it is impeachable as an abuse of power and possibly as an act of bribery. So they decide, like Graham, to ignore the evidence. The main way they’ve done this is to condemn the process of the impeachment inquiry as corrupt and, therefore, the evidence it has gathered as illegitimate—in the same sense that evidence improperly seized by police would be thrown out in a trial.

But as the transcripts of the hearings have been made public, this final line of defense has crumbled too. First, the hearings were not partisan, much less “Soviet-style” show trials, as Rep. Steve Scalise, the House minority whip, put it while displaying a picture of St. Basil’s Cathedral (the least Soviet-style structure in Moscow’s Red Square). The transcripts list all the House members who attended, and, it turns out, they included several Republicans. (As had long been stated, all members of the House Intelligence, Foreign Affairs, and Judiciary committees were authorized to attend the hearings.)

Republicans, as well as Democrats, were also permitted to ask testifiers questions. The Republicans’ main problem was that the witnesses didn’t leave them much room to score points. During the deposition of Marie Yovanovitch, the former ambassador to Ukraine, some Republicans probed for signs that she was biased against Trump. At one point, North Carolina Republican Mark Meadows—who was plowing that field most strenuously—asked how she came by the nickname “Masha.”* Yovanovitch replied that she’s “half Russian, and it’s a Russian nickname.” Meadows abruptly ended his questioning, though he had some time left to ask more.

Trying to discredit critical witnesses, cherry-picking evidence, changing an argument to its opposite in order to defend the leader—to some extent, this is politics as usual, indulged in by both parties. But something different is going on here, and if it persists without penalty, it may have—even compared with the many degradations that the Trump era has inflicted on American politics—the most degrading impact of them all.

Not only are Trump and his defenders sidestepping the most basic facts, not only are they undermining the primacy of facts as the foundation of debate and democracy, they are turning gaslighting—a form of psychological manipulation to make people question their own perceptions, memories, views of right and wrong and reality, so as to make them more and more dependent on the manipulator—into a permanent political condition. If this continues, everything in politics—domestic and international—dwindles into pretense and theatrics. The people and their leaders become mutual enablers in an ever-deepening cynicism. It’s not that nobody can trust anything any politician says again; it’s that mistrust becomes assumed as a given.

It is stupefying—or maybe it is completely predictable—that a self-obsessed showman like Donald Trump has led us into this rot. The question is whether any prominent Republicans will snap their comrades out of the spell.

Correction, Nov. 7, 2019: An earlier version of this article misidentified Rep. Mark Meadows’ home state. He is from North Carolina, not Louisiana.