Because of its genealogy and a shared commitment to racial justice, the Black Lives Matter (BLM) movement might be expected to have strong cooperative links with community organizing groups. Close, localized study of the interactions between these two approaches to social change reveals, however, something quite different. Far from being harmonious, the relations between BLM and community organizing prove to be marked by distrust, sometimes competition, and, more sporadically, cooperation. This article, based on ethnographic surveys in Los Angeles and Chicago, investigates how the BLM movement deployed and took root at the local level and how it interacted with community organizing groups in both cities. Emphasizing the importance of blending a meso-sociological level of analysis with a micro-sociological approach, we argue that the relations of competition and distinction, embodied in distinct group styles, repertoires of action, and organizational forms, can be explained by taking into account the actors’ resources, social properties, socializations, and trajectories. The article’s comparative perspective also shows that forms of cooperation may exist despite competition, and that cooperation is made possible in particular by younger people playing a bridging role.