Yes, and the SPD banned anti-war socialists and communists in 1918, and then ordered to have leaders of the KPD shot in 1920. As you surely know, 1920 is before

Yes, and the SPD banned anti-war socialists and communists in 1918, and then ordered to have leaders of the KPD shot in 1920. As you surely know, 1920 is before 1924. The point being, the KPD and the SPD were irrevocably alienated from each other past the point of no return before Stalin took power.