Maybe he is saving for a run for president. Hint, we could really use someone this election cycle to vote for!
MMM may not be old enough yet though...how old is he?
MMM isn't a natural-born citizen unless one of his parents is an American, Ted Cruz-style.
Maybe he'll run for prime minister then annex the US as part of Canada. At this point that manoeuvre might do us a favour.
It's much more likely that parts of Canada will secede to join the USA. It's legal, and could make sense for a few of the provinces.
From what I can recall, having lived in Alberta 22 years (it's the most American-friendly province), nothing in the world could be more unlikely. The USA is regarded as a nice place to visit or maybe work for a short period of time, and lots of elderly people "fly south" for the winter to avoid cold weather. But very few people want to actually live here full-time because the up-side doesn't justify the down-side. They like to do business with us, but they don't want to *be* us.
Provinces also have far more rights than states do. With the exception of slavery, which has never been legal in the colonies that later became Canada, Canadian provinces have all the rights that the Southern secessionist states wanted but didn't get.