Actually it's not a huge leap. All it takes is one lunatic to get into power, and he can then use the hatreds of the masses to whip up a frenzy. The Holocaust did not happen overnight, nor was it possible due to only one man.
You don't think Jews were rounded up and killed before Hitler? You show a breathtaking ignorance of history.
Hitler was just the culmination of something that might somewhat uncharitably be called an ingrained European behaviour pattern (or psychosis). Today's American Nazis mouth slogans such as "Next Time, Bigger Ovens".
And you personally run around claiming that Jews are somehow "different" - they're liberals, supporters of a socialist agenda. Hmmm... did you mean to say "not quite American"? "Disloyal"? "Christkillers"?
Or did you just think: oven fuel?