The worst decade in the history of the Liberal Party of Canada came to an end on October 19, 2015. Justin Trudeau swept to power, ending the ten-year rule of Stephen Harper's Conservatives. Trudeau's vision was relentlessly optimistic: the word "positive" was heard eight times in his victory speech, along with references to "sunny ways" and "hope and hard work." But the fates decreed that he would govern in darker times. His rookie...