Maybe the US will break up, and then some parts of the US will join Canada.
As big as the political problems the US has been having in recent years are, I don't think that's likely to happen in the short-to-medium term. But, if these problems just keep on getting worse, then eventually it may become a very real possibility.
Peter Zeihan makes the case in one of his books for why Alberta should leave Canada and join the US. I’m not Canadian or American and have no dog in the fight, but it’s interesting reading.
While Alberta is often called “the Texas of Canada” there is not a single Albert a that would give up their healthcare to join the US. In many meaningful ways their standard of living would plummet overnight - healthcare, education, safety, violent crime, life expectancy, etc.
Interestingly enough while the Canadian constitution doesn’t flat out permits this, it does allow the province to have a binding referendum and should a vote come to pass by it’s people, it forces the federal government to seriously consider it, thus a faithful negotiating can take place which could lead to the province becoming a sovereign nation.
As big as the political problems the US has been having in recent years are, I don't think that's likely to happen in the short-to-medium term. But, if these problems just keep on getting worse, then eventually it may become a very real possibility.