I never saw "promoting marxism" as part of the BLM mission statement. I am aware that a couple of BLM organizers acknowledge being marxist. That said, BLM is about "black lives" not about "socialism, marxism, or communism." Beyond that, the Democratic Party is 100% a "free-market capitalist party." And have been for some time. They are the preferred party of Wall Street, after all. The socialism boogeyman is just a shadow in your closet.