Feat of mental gymnastics. They consider themselves a looser sense of democratic that isn't a liberal multiparty democracy with competitive elections. With a twist of idealization, they rationalize that their dictatorship of the proletariat headed by a one-party leader serves the people: their bottom-up hierarchy of councils culminates to their single-party leadership whose final decisions (that close discussion and demand absolute obedience) somehow reflect the collective/people. They might call it democratic centralism or dress it up in more elaborate pseudotheoretical jargon.