Monday is the end of voting in Canada to elect a new prime minister. The big issue in this campaign has been U.S.-Canadian relations, especially Trump’s tariffs. Since the beginning of the year, opinion polls have gone from showing a commanding Conservative Party lead to a narrower but consistent Liberal Party lead. John Yang speaks with David Frum, a writer for The Atlantic, for more. PBS News is supported by - https://www.pbs.org/newshour/about/funders