For many decades, "Socialist" was used to refer to reformists , and "Communist" to revolutionaries ; socialist were for reforming capitalism , but not abolishing it, not sublating it . So, in that tradition of usage of terms, Bernie is consistent . He is also consistent with the US Socialists who during the "Cold" War had to denounce the Union of Soviet _Socialist_ Republics as unDemocratic less they go to prison or become politically and socially illicit like the Communist Party USA. So , Bernie's emphasis on "democratic " to distinguish himself from the "Stalinist" Communists is as old as the "Cold" War.