Justin Trudeau’s Liberals faced yet another major by-election loss in the Montreal constituency of LaSalle-Émard-Verdun yesterday, making for two consecutive electoral setbacks within months after the loss of Toronto-St Paul to the Conservatives in June. This time, the ruling party’s candidate Laura Palestini lost by a few hundred votes to Louis-Philippe Sauvé of the separatist Bloc Québécois, the main opponent in the province of Quebec. The Liberals not only lost...