After a year of plummeting poll numbers for Canada’s ruling Liberal Party, a shock defeat in a Toronto by-election marked a turning point. The loss in a Liberal stronghold is widely seen as setting off the chain of events leading to Justin Trudeau’s resignation and Monday’s federal election.

The US president came to dominate on the campaign trail, with the contest being viewed as a referendum on how Canada should engage with him.

President Trump has put his thumb on Canada’s pivotal national election taking place Monday in an extraordinary way, repeating his desire to make the country the 51st U.S. state. On Monday morning, just as polls were opening in Canada,