The West is abuzz with reports of a populist wave: rolling through Europe, sweeping across the Atlantic, and crashing into Gomorrah-by-the-Potomac. Donald Trump’s election as president of the United States—a watershed event as unthinkable as it was improbable to many across the ideological spectrum of American punditry—followed hard on the British people’s vote to exit the European Union, a cognate popular rejection of bipartisan elite opinion.

In short order, Matteo Renzi was the next shoe to drop. Italy’s now-former prime minister, a young, attractive, politically “progressive” technocrat, darling of the European cognoscenti, had been hailed—it seemed like only yesterday—as Rome’s (or is it Brussels’s?) answer to Barack Obama. He resigned in November, though, after the Italian people resoundingly defeated his proposed constitutional “reform.” The scare-quotes are offered advisedly: Italy having been virtually ungovernable since Garibaldi forced what passes for its unification, Sig. Renzi’s reform was a scheme to end the paralysis by accreting power to himself at the expense of the legislature. Think of it as a gambit to codify U.S. President Barack Obama’s “I’ve got a pen and I’ve got a phone” style of centralized rule.

The victorious Trump had the populist wind at his back. Thus, efforts to caricature the real-estate mogul and reality-television star as a budding Hitler fell flat. Renzi, by contrast, ran into the teeth of that wind. The hyperbole casting him as a would-be Mussolini took its toll.

Renzi’s fall is the continental aftershock of the Brexit earthquake. The “Remain”