Have you ever looked at a Canadian Conservative Party Platform? On some things they're further to the right than American Republicans. Canadians are in a completely different political context than American counterparts and there are no direct equivalencies. Canada is a large petroleum exporter and petroleum producing companies are much more influential there than in most of the U.S. Canadians may share more of a cultural affinity with contemporary Democrats, but their issues are nowhere near the same and that affinity would be gone if they had to come up with a common platform. Yes, there'd probably be a little less evangelicalism in politics overall (again, that's more the political culture than the politics itself).
Again though, this is all assuming that an annexed Canada would be granted statehood in the Union, and there's no precedent for that happening when the U.S. government decides to annex a territory without sufficient support already in place. (Out of 50 current states, 31 were territories first. The thirteen colonies, Vermont, Kentucky (started off as southwestern Virginia, i.e., one of the 13 colonies), Maine (split off from Massachusetts in 1820, i.e., one of the 13 colonies), Texas (invaded by Americans that fought to keep it independent from Spain first, and then from México, established a government similar in form and principle to other state governments, and uniquely annexed by treaty), California (Compromise of 1850, and again with a sudden influx of Americans establishing a government similar to other state governments).)
Canada, even in this bizarre scenario, meets none of those criteria. Were it annexed, it would likely be an unorganized (Congress not creating a new government for it; not even a non-voting delegate sent to Congress) unincorporated (limited application of U.S. Constitution, including the Bill of Rights) territory.
However, even should Palin be elected in 2012, that nightmare scenario for Canada is just nonsense.