“The natural state of the Democratic Party might actually be to argue,” said Jim Kessler, executive vice-president for policy at Third Way, an organization of moderate Democrats. “The people who vote for Democrats are moderates, but the activism and the money comes from the more progressive wing of the party. It produces a natural split that the Republicans ordinarily don’t have because usually the money, the activism and votes all come from the same place. Trump upended that, and that’s why we’re in a situation that probably has no precedent.”

The result is an unusual and toxic alchemy: hyperpartisanship at a time of party divisions. This is a twin crisis for the established political order that Canada has seldom, if ever, experienced. There were, to be sure, two competing Canadian parties on the right that united under Stephen Harper in 2003 but, as Daniel Béland, director of the McGill Institute for the Study of Canada, put it, “We haven’t had two splits at the same time anywhere near the level of the party divisions in the United States today.”