Aaron Moore plays Donald Trump in Brittany Johnson’s production, at Barnard College, of Aristophanes’ “Knights,” retooled around the current Presidential election. Photograph by Noah Zinsmeister

One of the best-selling Halloween items on Amazon right now is a floppy blond wig called “Mr. Billionaire.” At Barnard College one recent evening, a student named Aaron Moore pulled one over his brown hair, as he and a troupe of actors prepared for the opening night of a production of Aristophanes’ “Knights.” A comedy written for Athenians of 424 B.C., the play had been retooled around the current Presidential election by Brittany Johnson, who also directed.

Members of the Greek chorus, all failed 2016 Republican Presidential candidates, were adjusting their charcoal-gray suits backstage. Molly Cavanaugh, who played Marco Rubio, had asked her stylist to give her a hairdo just like the Florida senator’s. “I asked for something I could undo the day after we close,” she said. (When, earlier, the cast had posed in costume for a publicity photograph on the Columbia campus, a group of Chinese tourists clustered around, as if they’d happened upon the real thing.)

Johnson, whose day job is teaching classics at a New Rochelle prep school, had made an offbeat choice in updating the little-known “Knights.” Adapters of Aristophanes usually choose “Lysistrata,” a cheery fantasy about a Panhellenic sex strike that achieves international peace. “Knights” has a darker premise: that democratic leadership is always getting worse. It tells the story of the leatherworker Cleon, Athens’s reigning populist at the time, being overthrown by an even lowlier, more cunning rival, named for his noisome trade: the Sausage-seller.

“All of Aristophanes’ comedy is a little bit dark,” Johnson said backstage, noting that the logic of “Knights” had required Donald Trump to be the modern-day counterpart to the unscrupulous, but ultimately triumphant, Sausage-seller. That meant that the role of Cleon—a panderer and manipulator based on a real Athenian, satirized so viciously that Aristophanes reportedly played the part himself rather than expose another actor to a libel suit—had to go to Hillary Clinton. The play presents the contest between them as a race to the bottom, with the Demos, or citizenry, reimagined here as a gaggle of female newscasters, anointing Trump as its new champion.

“Knights” was written about five years after the death of Pericles, and it captures the mood of an Athens desperate for leadership. It contains the earliest known usage of the Greek word “demagogy,” and a related adjective, in a scene in which the Sausage-seller, plucked from the gutter, is being groomed to take power. The strict definition of d_emagogia_, “leadership of the people,” might well have been regarded as a virtue in democratic Athens, but by the time the term was coined it was already cynically linked to shysterism and shamelessness.

“You’ve got all the demagogic arts: a loud, annoying voice, low origins, and you’re a man of the marketplace,” one of the Sausage-seller’s handlers tells him, urging him to challenge Cleon. The Sausage-seller protests that he has no education or skills, and can barely read; he is told that “demagogy demands neither learning nor moral fibre, but sits best on an ignoramus and a bdeluros.” That marvellously untranslatable noun, connected to a word for flatulence, connotes a crudeness that induces nausea and disgust.

Johnson first adapted Aristophanes at Bowdoin College, where she put on an update of “Acharnians” as a senior project, in 2012. Two years later, as a master’s candidate in classics at Columbia, she wrote and directed a version of “Clouds,” the playwright’s bitter attack on Socrates and his “Thinkery.” After reading her script, which featured a chorus of caustic clouds, representing Socrates’ airy-fairy divinities, reimagined as a posse of bogus female academics, Columbia withdrew funding. The show went on nonetheless.

For the updated “Knights,” Johnson transformed the chorus, originally made up of Athenian citizens wealthy enough to own horses, into a boisterous ensemble of Trump’s former Republican rivals, who have opportunistically become his anxious, but outwardly enthusiastic, supporters. Johnson said that she found the play’s message “creepy,” adding that she is a Bernie Sanders supporter. At one point in “Knights,” the chorus sings, “Hard not to be outspoken / when your political system’s broken,” to the tune of Don McLean’s “American Pie.”

As the play neared its resolution on opening night, Moore, as Trump, gazed at his cell-phone screen, on which various “Oracles” were trying to advise him, and declared, “The future is vague, and so am I. Therefore, I am the future.” In the safe space of a play more than two thousand years old, that line raised gales of laughter.

Afterward, Johnson said that, while she loved adapting Aristophanes’ dialogue for Trump, “the things he says in the play have recently been proved _believably _horrible rather than unbelievably horrible, which makes the play even more haunting to me.” She continued, “I wonder, have I helped to ‘normalize’ Trump?”