Following the Brexit referendum, one would have thought that Britain’s political class would be wary of launching unnecessary battles in which there’s no certainty of victory and divisiveness is a foregone conclusion. But apparently Labour’s parliamentarians didn’t get the memo.

So the day after Britain voted to leave the European Union, with Prime Minister David Cameron having announced his resignation and the Conservative Party in chaos, two senior Labour Party figures resolved not to attack their opponents when they were weak, but rather to turn their fire on their own leader. They submitted a vote of no confidence in Jeremy Corbyn, the left-winger who was elected with a thumping majority less than a year ago. But because they mistook their long-standing grievance for a plan and their own echo chamber for the clarion call of insurrection, their strategy pretty much stopped there.

Corbyn had stood on an anti-austerity and pro-peace platform, against a bland range of managerial nonentities who stood for little beyond office. Among the party’s grandees, his victory was not understood as a signal that Labour had to make a left turn in order to hang on to its base. Instead, it was received as a huge collective brain fart by a disgruntled membership that could no longer be entrusted with the grave responsibilities of democracy if they were going to make such bad choices.

Having failed to come to terms with the root causes of Corbyn’s victory, the grandees had no candidate to replace him, no alternative policies with which to challenge him, and no notion of how to win over those members and unions who had chosen him. For nine months, the party’s establishment has obsessed over how to get rid of the man whose leadership it never considered legitimate. And this was what it came up with: a tantrum.

There were two pretexts for this attempted coup. The first was that Corbyn had campaigned to remain in the EU with insufficient zeal. The other was that with Cameron gone, a general election scheduled for 2020 could well be brought forward, and Corbyn couldn’t win it. The poor couldn’t wait.

Neither claim held much water. Sixty-three percent of those who voted Labour in the last election voted to stay in the EU—which means Labour voted broadly in line with the Scottish National Party, whose leader emerged from the referendum being hailed as a great success. “There is little evidence that Mr. Corbyn’s campaigning efforts—or those of any other Labour politician—made much difference either way to the willingness of Labour supporters to vote for ‘remain,’”

John Curtice, one of Britain’s most prominent nonpartisan election analysts. “A split in Labour’s ranks was in evidence from the moment the referendum was called—and the picture simply did not change during the subsequent months of campaigning.”