Four months since Mark Carney was elected prime minister, journalist Justin Ling is examining the forces that drove – and divided – Canadians during the federal election campaign in his new book, The 51st State Votes. David Common speaks with Ling about the existential crisis Canadians faced at the ballot box in the form of Donald Trump, how it fundamentally shifted the fortunes of Conservative leader Pierre Poilieve, and how all federal parties need to adapt to meet this moment as Parliament gets ready to return.