Quirky Canada has own government, laws

Speaking of separatists, why is it that Canada has a robust, and rising, separatist movement, while America doesn't? It's not just Quebec. Newfoundland, which has always been suspicious of fraud in the referendum that propelled it into the union, now has a separatist party (although to be sure, it's clearly not a very successful one.) Alberta's Separatist candidates don't get much of the provincial vote, but they seem to be gaining sympathy and support. And I've now met several people from British Columbia who say that if Alberta broke off, they'd like to join them.

Perhaps my vision is just skewed by the fact that I've actually met multiple English-speaking Canadian separatists, but the Canadian union seems to be much more fragile than the American one, and not just because we know what to do with hotheads who try to leave the union. Why would this be?

My working theory is that it is the wild population asymmetry in Canada; given the parliamentary structure, the Liberal Party just needs to run up the vote total in Toronto, and not do too badly in Quebec, and it gets to run things. (A nasty corruption scandal propelled the re-formed Conservatives into a minority government last election, but it looks like they'll be out of power again soon.) That is just what it has been doing for the last decade or so, and as a result, the people in the other 3.4 million square miles are getting a mite restless. Can my readers offer a better explanation?