Omiccioli was also active in politics and, with Mario Mafai, Guttuso and Afro, he created the first header of the Italian communist newspaper "L’Unità" in 1945, immediately after the Italian "Liberazione". During the same year he exhibited at the "I Mostra dell'Arte" against barbarism, promoted by this newspaper at the Gallery of Rome with catalogue by Antonello Trombadori, presenting a dramatic political painting by the title "La fucilazione di Bruno Buozzi" ("The Fusillading of Bruno Buozzi"").