What is the relationship between the struggle against racism and socialist theory and practice in the United States? Why should people of color active in antiracist movements take democratic socialism seriously? And how can American socialists today learn from inadequate attempts by socialists in the past to understand the complexity of racism? In this pamphlet, I try to address these crucial questions facing the democratic socialist movement. First, I examine past Marxist efforts to comprehend what racism is and how it operates in varying contexts. Second, I attempt to develop a new conception of racism which builds upon, yet goes beyond the Marxist tradition. Third, I examine how this new conception sheds light on the roles of racism in the American past and present. Last, I try to show that the struggle against racism is both morally and politically necessary for democratic socialists.