AskHistorians

If by some miracle the SDP pulled off a surprise victory and righted the floundering ship that was the German Weimar Republic, we'd probably discuss evil in terms of colonialist or Soviet atrocities.

Fascism is a very easy target for condemning authoritarians, though - if you ever read the Doctrine of Fascism, it's really quite open about crushing the individual in service to a singular will in control of the fascist state. We'd probably still be calling people fascists for being authoritarian shitheads - we'd just probably use a broader term than 'Nazi' ('genocidaire' is my vote, but it's also a bit of a mouthful) when casually referring to immense evil.