Nazi Germany was not a democracy. Weimar Republic was a democracy, with a weak political system that allowed plurality (not majority) Nazis to take over the government. In 1932, Nazi got 37% (19% jump over 1928), Commies 14% (so you can say totalitarians got more than 50%). Most of this 19% increase came at the expense of very small parties, who each lost 1-3%. Social Democrats lost only 3%.
That is why it is important to watch out for “experiments” in the American system that will not lead to similar problems.