On Aug. 19, 2015, shortly after midnight, the brothers Stephen and Scott Leader assaulted Guillermo Rodriguez. Rodriguez had been sleeping near a train station in Boston. The Leader brothers beat him with a metal pipe, breaking his nose and bruising his ribs, and called him a “wetback.” They urinated on him. “All these illegals need to be deported,” they are said to have declared during the attack. The brothers were fans of the candidate who would go on to win the Republican party’s presidential nomination. Told of the incident at the time, that candidate said: “People who are following me are very passionate. They love this country, and they want this country to be great again.”

That was the moment when my mental alarm bells, already ringing, went amok. There were many other astonishing events to come — the accounts of sexual violence, the evidence of racism, the promise of torture, the advocacy of war crimes — but the assault on Rodriguez, as well as the largely tolerant response to it, was a marker. Some people were outraged, but outrage soon became its own ineffectual reflex. Others found a rich vein of humor in the parade of obscenities and cruelties. Others simply took a view similar to that of the character Botard in Ionesco’s play: “I don’t mean to be offensive. But I don’t believe a word of it. No rhinoceros has ever been seen in this country!”

In the early hours of Nov. 9, 2016, the winner of the presidential election was declared. As the day unfolded, the extent to which a moral rhinoceritis had taken hold was apparent. People magazine had a giddy piece about the president-elect’s daughter and her family, a sequence of photos that they headlined “way too cute.” In The New York Times, one opinion piece suggested that the belligerent bigot’s supporters ought not be shamed. Another asked whether this president-elect could be a good president and found cause for optimism. Cable news anchors were able to express their surprise at the outcome of the election, but not in any way vocalize their fury. All around were the unmistakable signs of normalization in progress. So many were falling into line without being pushed. It was happening at tremendous speed, like a contagion. And it was catching even those whose plan was, like Dudard’s in “Rhinoceros,” to criticize “from the inside.”

Evil settles into everyday life when people are unable or unwilling to recognize it. It makes its home among us when we are keen to minimize it or describe it as something else. This is not a process that began a week or month or year ago. It did not begin with drone assassinations, or with the war on Iraq. Evil has always been here. But now it has taken on a totalitarian tone.

At the end of “Rhinoceros,” Daisy finds the call of the herd irresistible. Her skin goes green, she develops a horn, she’s gone. Berenger, imperfect, all alone, is racked by doubts. He is determined to keep his humanity, but looking in the mirror, he suddenly finds himself quite strange. He feels like a monster for being so out of step with the consensus. He is afraid of what this independence will cost him. But he keeps his resolve, and refuses to accept the horrible new normalcy. He’ll put up a fight, he says. “I’m not capitulating!”