"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."
Were the party system changes before then more due to
a major party crushing the other major party, and then splitting, or
a minor party growing and eventually replacing one of the two major parties?
Bonus points if anyone has a source on this.
October Surprise comes to mind.