In 1921 he became one of the founding fathers of the Communist Party of Italy.[1] Bombacci was a friend of future Italian Fascist dictator Benito Mussolini. He was expelled from the Communist Party in 1927 for embracing a pro-Fascist position.[2] From 1927 onwards Bombacci became an open Fascist, although he never officially joined the National Fascist Party. After Mussolini was ousted as Prime Minister of the Kingdom of Italy in 1943, Bombacci remained loyal to Mussolini and tried to help him legitimize the Italian Social Republic and relegitimize Italian Fascism.[3]