Open this photo in gallery: Canada's Prime Minister Mark Carney attends a rally during his Liberal Party election campaign tour in Laval, Que., on April 22.Carlos Osorio/Reuters During a campaign stop in Calgary two weeks ago, Mark Carney acknowledged there had been a cost to his party’s efforts to guard against foreign interference during the race that made him the new Liberal Leader. A reporter had asked him what he would do to stave off foreign meddling in nomination and leadership contests. He cited the “rigorous process” the party had used this spring in choosing a leader. “Fewer people would...