 In 1918 the radical wing of the Labour Party assumed control of the party at the national convention.Vidnes stepped down from the central committee, and from the positions as chairman of Socialdemokratiske Presseforening and chief editor of "Social-Demokraten".In a piece called "Arbeiderpartiet gaar helt over til bolsjevismen" published in the right-wing newspaper "Tidens Tegn" in May 1919 he denounced the "Bolshevism" in the Labour Party.