Maybe you should get your Facts right. The KPD only didnt participate in the 1919 election. In the last Reichstags eleciton in 1933 they got 12,3%. They where removed and procecuted after the Nazis blamed a Communist for the Reichstags fire. idk much about Italy but they also got a few seats before Mussolini. To your question about what happened to German Communists, they where either put into Prisons/KZs and killed there, flead to the Soviets or went to Spain to fight Facism there. idk about Italy but probalby the same.