Nazi Party: 1928, 2%. 1930, 18%. July 1932, 37%...
I believe in democracy, but I also know that Nazis can get 43.9% as they did in March of 1933.
The more layers of democracy you have, the more bumps in the road you put for Nazis. The constitutional structure of the Weimar Republic slowed Hitler down. Modern Canada's would not.
I'm sorry to say so, but what this shows is that you do not believe in democracy at all. You cite an example of when democracy failed, and you suggest that we must find means of preventing a recurrence. This is reasonable, except that the means you propose are to cripple democracy by limiting participation in some way that you think will prevent bad people and bad parties from getting a foothold. Of course, the meaning of "bad" is just a tad subjective, and any rule that could be used to eliminate Nazis could also be abused to eliminate socialists, or greens.
My question is, why are you so sure that your own ideas and beliefs, your ability to tell right from wrong, are superior to those of others? Perhaps you or I would have been convinced of the virtues of Nazism if we had been unemployed German workers with 4 kids in 1930. I submit that you are expressing your fear of what people who are not you might vote for if they aren't properly restrained. Whatever you want to call that, it isn't belief in democracy.