Good point - these could most likely be exploited as well. That's another way for the US to get there. Break up Canada. The Quebecois get to be their own mini-nation. Not sure what would happen to the Maritimes or Newfoundland. And it's not like Western Canada is uncontroversial, look how much people bag on Alberta.

The thing that would for sure not happen is Canada becoming an actual state in the US. Way too liberal for that and logistically it wouldn't make sense.