Without these black swans, Brooks suggests, Trump’s candidacy would be as implausible now as conventional wisdom saw it to be a year ago.

But the populist anger it draws its power from would be there just the same. According to New America’s Anne Marie Slaughter, for all the Trump campaign has used xenophobia and other modes of bigotry to draw out support from radical elements of the Republican base, they are not the real catalysts of populist revolt on the American right today. The real catalysts are a set of deep disruptions in the American economy—a constellation of forces that also accounts for much of the Bernie Sanders phenomenon, as far as it’s gone.

“What we are seeing is anger at a disruption of our economy and, really, our social order—of the magnitude we saw when the agricultural age gave way to the industrial age,” Slaughter says:

When the industrial age completely upended the way people lived and worked, from small cottage-industry, farming villages to going to factories, in another place from your family, to work—which is the same kind of profound upheaval we’re seeing now, we got Marxism. We got Marxism, and then we got World War I, and then we got World War II—that upheaval … was a direct outgrowth of the changes wrought by the industrial revolution. That is what we are seeing the beginnings of today. The digital revolution … is completely upending how we work, what the sources of value are, how people can support their families, if they can at all, and creates tremendous fear and rage in the sense that you are at the mercy of forces you cannot control.

But as fraught as these feelings are, they’re not political problems on their own terms.

“There’s nothing inherently wrong with anger in American politics,” says Stephen L. Carter of Yale Law School. “It’s not inherently bad. If it were inherently bad, we’d be in a lot of trouble, because anger has been a feature of our political system since George Washington decided not to run for a third term and retired, and we had to decide who was going to replace him. Unreasoning anger has been a feature of politics for a very long time.”

Brooks emphasizes that political anger isn’t just chronic; it’s often fitting and politically vital. “We shouldn’t regret the presence of anger, necessarily, because anger, particularly justifiable anger, when we’re angry on behalf of people who have less power than we do, that’s a good thing,” Brooks says. “That’s actually the mark of a good society—that’s the nature of a politics that’s actually standing up for people who are powerless, people who are at the periphery of society.”

“The problem is when anger is the salient characteristic of a political system. And that has a name: It’s populism. And populism is driven by grievance; and grievance is the rocket fuel of an anger that becomes truly salient, that becomes truly central to the political system.”