Antifa was in Germany from the 1920s. It was the paramilitary arm of the Soviet-aligned Communist Party. It used the same tactics then, and caused people to support the Nazis as the only group willing to fight them.
The Nazis (National Socialist German Workers Party), the Communists, and the Italian Fascists were all just different flavors of socialism.
And then many of those Antifa eventually became good little Nazis.