Canada and the US have such distinct cultures. It would be shameful to merge them.
Ha. I see the Northern United States everywhere but Quebec and the remnants of Acadia. Even if Canada is distinct from the actual northern US, it's still a much smaller difference; Ontario and Massachusetts have more in common than Massachusetts and Alabama.
However there is a difference in political culture at least somewhat. So while I'd love to see a full unification a schengen style situation is a more reasonable and rational goal that will benefit both countries and won't be as difficult for some American conservatives and Canadian nationalists (lol) to swallow. Let Canadians and Americans enter and exit both nations without unnecessary bureaucracy or fuss.