Politicians who rail against elites have no difficulty finding a receptive audience. Disenchantment with the status quo, however vaguely focused, has created populist heroes from figures as diverse and unlikely as Donald Trump, Bernie Sanders and Jeremy Corbyn.
But, as Mr. Corbyn is now discovering amid the post-Brexit quarreling in Britain's Labour Party, it's not enough for a political leader to be a vehicle for other people's anger. At a certain point you actually have to lead – which in Mr. Corbyn's case should have required him to inspire confidence among Labour MPs who hope to form the next government in Westminster after Prime Minister David Cameron's resignation.
Mr. Corbyn has failed this test badly in recent days. But with the supreme indifference that's characteristic of populist leaders who think they talk directly to the people, he doesn't much care what his fellow MPs think about him.
Which may be just as well, since they don't like him at all. On Tuesday, a no-confidence motion against his leadership passed by an overwhelming 172 to 40. To put that crushing rejection into perspective, Margaret Thatcher was persuaded to quit as prime minister in 1990 after winning the support of 55 per cent of her MPs.
And yet Mr. Corbyn refuses to resign. In any kind of representative democracy, claims to leadership usually become invalid when the followers refuse to follow.
But Mr. Corbyn, like Mr. Trump, doesn't believe in the political system that has elevated him to insider status. When things go wrong, he can always point to the tens of thousands of people at the grass-roots level who helped him win the top prize – a self-serving definition of the democratic process, to be sure, but one that taps into activists' distrust of elites, especially their own.
Like Mr. Sanders, Mr. Corbyn's popularity can be traced to the fact that he has rarely had to test his old-school socialist principles against modern economic realities. A nostalgic Euroskeptic, he did little to aid Labour's Remain campaign – his final failure as a so-called leader, since his inertia can only push Labour's disenchanted working-class base further to the right, and into the waiting hands of some other anti-elitist.