We've seen what happens when authoritarian governments which start locking minorities up in concentration camps progress to inventing historical grievances to start seizing territory. Appeasement doesn't work.
I am concerned about an authoritarianism in America, even more so if the president started saying stuff like: "Canada and the US are essentially the same people and should be one country. The Canadian government has always been propped up by foreigners to weaken us. Reunification must happen, by force if necessary."