"Progressives should not make the same mistake that Ernst Thälmann made in 1932. The leader of the German Communist Party, Thälmann saw mainstream liberals as his enemies, and so the center and left never joined forces against the Nazis. Thälmann famously said that ‘some Nazi trees must not be allowed to overshadow a forest’ of social democrats, whom he sneeringly called ‘social fascists.’
After Adolf Hitler gained power in 1933, Thälmann was arrested. He was shot on Hitler’s orders in Buchenwald concentration camp in 1944."
Hitler didn’t win because he beat Hindenburg after Thälmann split the vote. He lost to Hindenburg, the center-right candidate endorsed by the social democrats, then won anyway because Hindenburg appointed him Chancellor.
The social democrats were the ones who refused to back Thälmann, the only anti-Hitler candidate in the race. And the same way that the communists called them “social fascists,” the social democrats used similar rhetoric, frequently saying that the communists were no different from the Nazis, that there was no difference between the far left and the far right.
But also, we don’t have to keep rehashing 100 year old grudges from another continent.