That didn't really get results for at least a generation after the Nazis, which is a long time to wait in this environment. And there was an occupying army for decades afterward, so even if something went wrong, the threat of Nazis could be nipped in the bud through extra-parliamentary means. Canada can't occupy the entire heartland and south alone, and the Europeans won't stay forever. There's no safety blanket. Also: Rumsfeld lost the popular vote twice, but he still got way more votes than Hitler ever did. That's cause for greater cynicism about the American people, especially in certain regions.