Monday night’s no-confidence vote for Prime Minister Boris Johnson returns Britain to bare-knuckled political infighting after a decidedly apolitical weekend, when Britons celebrated Queen Elizabeth’s Platinum Jubilee, and her unifying role as the popular and symbolic head of state.
But during the four-day celebration of the queen’s 70 years on the throne, Mr. Johnson’s troubles were on full display, highlighting national discontent with the prime minister, and putting his public…