What do we call a man who turns on everything he once claimed to believe? For a practitioner of petty and self-serving duplicity, we use “sellout” or “backstabber.” (Sometimes we impugn the animal kingdom and call him a rat, a skunk, or a weasel.) For grand betrayals of weightier loyalties—country and faith—we invoke the more solemn terms of “traitor” or “apostate.”

But what should we call J. D. Vance, the self-described hillbilly turned Marine turned Ivy League law-school graduate turned venture capitalist turned Senate candidate? Words fail. His perfidy to his own people in Ohio is too big to allow him to escape with the label of “opportunist,” and yet the shabbiness and absurdity of his Senate campaign is too small to brand him a defector or a heretic.

My friend Preet Bharara, the former U.S. attorney for the Southern District of New York, tried to describe Vance recently and came up with “pathetic loser poser fake jerk,” but that is a lot of words. To distill the essence of Vance as a public figure, the word that enters my mind is an anatomical reference beginning with the letter a.

I do not use that word lightly or comfortably. I am, in the formal sense, a man of letters. I have been an officer of instruction at several institutions of higher education (and I remind you here that I do not represent any of them and speak only for myself). I would not advise my students to use the term.

But the word is apt when I consider Vance’s silly and yet detestable moral collapse. Some people back in Vance’s home region of Appalachia thought his memoir, Hillbilly Elegy, was hollow and inaccurate, but for a time, other people—including me—were intrigued by his writing and public speaking. Vance lived as a child in a steel town in Ohio and spent his summers in the hills of eastern Kentucky, while I grew up amid the rotting factories of New England, solidly in the working class but not poor. I welcomed his willingness to cast a critical eye on his (and my) people, especially after years of conservative hand-wringing focused solely on the dysfunction of minority communities.

Vance gained early support in the political center, particularly among conservatives. The American working poor, no matter where they are, do in fact need civic representatives from the center-right, people who can talk candidly about the limits of government and who can make a moral case for tough love and personal responsibility, but one based on a sense of shared experience, common values, and genuine compassion. Someone like Vance could be that candidate.

Someone like Vance, perhaps, but as we now know, not Vance himself. Not so long ago, he talked about the self-defeating bias against education among poor whites. He acknowledged the self-destructive habits of some of the people he grew up around. Vance wrote, in this very magazine, that Donald Trump “is cultural heroin”—a powerful charge from someone who hails from the epicenter of the opioid epidemic—and provided a “quick high” that could not fix what ails the country. All of that vanished once Vance decided he wanted to go to Washington—and after the Trump supporter Peter Thiel dropped $10 million into a political action committee.