Others read the costume as symptomatic of Canada’s racist history generally, and in particular its history with minstrel shows, which is more extensive than you might think. (The composer of Canada’s national anthem performed in blackface.) Others, such as the society gossip columnist Shinan Govani, have acknowledged personal conflicts: “It is the season of moral gymnastics, here in Canada,” he wrote in the Daily Beast.

Needless to say, dispassionate debate about the significance of Trudeau’s costume—parsing his intentions and the context—is not possible, given that we’re in the middle of an election. The picture went viral; that’s what counts. Liberal Party candidates have been struggling. “It was wrong then, and it’s wrong now,” Harjit Sajjan, the defense minister, told the CBC. “But I’m also here to talk about the person I know, in terms of how much he is standing up for people.”

Whatever Canadians may think about the photograph itself, it closes off a major line of attack for Trudeau. Live by the sword of political correctness, die by the sword of political correctness. You can’t argue that your opponents are a bunch of embarrassing antiquities living in the political past—by, say, replaying the Conservative leader’s 2005 speech opposing gay marriage, which the Liberals were doing right up until this story broke—when the internet is rife with your face in brown makeup.

David A. Graham: Canada’s surprising history of blackface

The Trudeau scandal points to a larger problem: The woke will always break your heart. It’s not just that nobody’s perfect, and it’s not just that times change, and it’s not even that the instinct to punish that defines so much of the left is inherently self-defeating. If people want to sell you morality, of any kind, they always have something to hide.

The main criticism from Trudeau’s opponents on the right has usually been that he’s a spoiled brat—a son of privilege—not up to running the country. A faker. The brownface debacle has now become, on the left, a symbol of his lack of real commitment to progressive values. But the cross-party consensus that Trudeau is slight and phony doesn’t survive even a cursory examination of his record. An independent assessment by two dozen Canadian academics found that Trudeau has kept 92 percent of his campaign promises, fully or partially, the most by any Canadian government in 35 years. He is measurably, demonstrably the most sincere and effective prime minister in living memory. He is the rare case of a man whose virtue-signaling has distracted from his real virtues.

Only the left struggles with these standards of style. Right-wing political opponents in Canada and elsewhere have a completely different understanding of acceptable behavior. In the United States, President Donald Trump’s supporters take his brand of nastiness, his aggressive rejection of even the most basic social norms, as a sign of authenticity. Meanwhile, Senator Elizabeth Warren is still apologizing for her Cherokee-ancestry claim.