Why does Trump want Canada as a state?

Is this about their natural resources, the fact that the American population is set to plateau and we need more workers? I can't see the political angle because Canada would more than likely be a blue state. Is this about Trump wanting to cement his legacy as an American President who expanded the American union by twice its land mass? Does he want to just consolidate our largest trading partner put of expediency?

It boggles the human brain that he would want to try this because Canadians are fiercely independent and would soundly reject economic or diplomatic overtures to become a state and an invasion of Canada would trigger Article 5 and be a never ending guerilla war according to military experts.