If you had spoken to a German Nazi in the late 1930s they would have explained to you how they stood for virtue, justice, and all things good. They would have explained how all their beliefs were based on "science", and to disagree with them was to go against the very facts of the universe. That to deny how right and just they are is no different than denying simple physics. They rely on a new moral certainty, and in such a way can justify almost anything (and they did/will).
All these things are hallmarks of totalitarianism. They come in different flavors, but the one thing they have in common is a rejection of traditional morality, and the adoption of a "new" morality. It is always a refrain on the same themes.
There is nothing new under the sun. It's a merry go round, and being ignorant of history is the cause. If I could do one thing to reverse it I would nuke "social studies" from all public education and put back HISTORY, where it belongs. They repeat all these mistakes because they're totally ignorant of them. They have zero skepticism because they only know the history of now.