What happened with the Nazis was a separate thing than the sporadic pogroms that occured for several centuries before then. Normally those were isolated and it was essentially people just taking shit out on an ''other,'' conveniently spurred on by things like blood libel.
What happened with the nazis was a whole different thing. They saw geopolitics as a evolutionary struggle between subspecies, with the germanic facing off against the semitic with various degrees of untermensch in between. They believed the germanic needed to win out, so the other needed to be extirpated root and stem.