Whether those leaders are concerned about leading for the benefit of the people, or their own personal power..
Have you ever seen a "benign" communist regime?
I think that's a contradiction in terms. Communism doesn't for the existence of human nature: competition, commerce, capitalism, God, spirituality, freedom of press, religion, free expression, freedom of assemble or "certain unalienable rights." They MUST be repressive, with a large, strong, active home army because their system of government is so anti-human.
I think communist leaders are corrupted by the very idea of what communism is: a fallacy, a hopeless, arrogance of Marx's illogical thesis.