Opinion | What Could Go Wrong With Boris Johnson’s Scheme? Everything

Since becoming prime minister in July, Boris Johnson has pursued two goals: exiting the European Union by Oct. 31 (“do or die”) and an early general election. He failed fairly decisively on the former, stymied by the same political stalemate that bedeviled his predecessor, but on Tuesday he got the elections, which will be held Dec. 12. The question is whether this will resolve or deepen the impasse over Brexit.

Mr. Johnson’s calculations are basic politics. The polls give him a strong edge; he has a Brexit deal ready to go; his brand of entertaining, irreverent populism is popular on the campaign trail; and his Labour opponent, Jeremy Corbyn, is unpopular. So: Mr. Johnson leads the Conservatives to a parliamentary majority, achieves Brexit and gets five years in power.

But the three-year struggle over Brexit has turned British politics inside out, and plenty could go wrong with Mr. Johnson’s scheme over the next six weeks. Most immediately, the House of Lords could still block the election, but that is the least likely problem. The greater problem was illustrated by Mr. Johnson’s predecessor, Theresa May, who called snap elections for June 2017 in the hope of translating strong polls into a stronger majority, only to lose the majority and find herself reduced to a nettlesome minority government.

That could easily happen again. Party loyalties have been sharply eroded by Brexit, and many voters are likely to be driven by how they stand on leaving the European Union rather than how they’ve voted in the past. In Scotland, where feelings run strongly against leaving the Union, for example, the Tories may lose seats. Mr. Johnson’s “do or die” pledge to quit the bloc by Thursday could also turn against him, along with his much-quoted declaration that he would rather be “dead in a ditch” than seek the extension that he was compelled to seek. That might nudge hard-core Brexiteers away from the Conservatives and toward Nigel Farage’s Brexit Party. Then there’s Mr. Johnson himself, whose dubious integrity will surely be exploited by his opponents.

The greater question is whether an election will end the convulsions of Brexit. The divide over relations with the European Union touches on fundamental questions of British identity and Britain’s place in the world, and it has only deepened in the three years since the fateful referendum in June 2016. About the only motion to consistently pass in Parliament has been against allowing a no-deal Brexit, which almost everybody believes would be catastrophic. (Mr. Johnson disagrees.) Every other attempt to secure or block Brexit has been stymied in a procession of votes and parliamentary maneuvers that would be comical if they weren’t so frustrating and momentous.

However the election plays out, the winner is certain to face a hostile and irreconcilable opposition. And even should Mr. Johnson win and get his Brexit bill through, this would only mark the start of a long transition period with many more tempestuous battles in Parliament, accompanied by new economic woes. A respected British think tank, the National Institute of Economic and Social Research, added to a large volume of pessimistic forecasts on Wednesday, predicting that even if Britain succeeded in negotiating a free-trade agreement with the Union, it would lose almost $100 billion over the next decade. The institute said the economy has already shrunk by about 2.5 percent since Britain voted to leave the bloc, and that will only worsen.

Yet in an impasse without any obvious or easy way out, a general election may well be the best of a dismal set of options. The current Parliament has exhausted its possibilities, and asking the public to choose a new one is how a parliamentary democracy is meant to deal with political deadlock. There is no guarantee that the debate will become wiser, more conclusive or more civil. But if there’s a chance that it might, at this stage it’s worth exploring.