Leftist and Marxist criticism considers identity politics as a reformist impulse that precludes a revolutionary model, an agent of amelioration rather than change. Marxist thinkers working on capitalism and the history of race formation disagree with an identity politics approach on the cause/effect relations of the problem and therefore how it should be tackled. There has been much debate in art, and other fields, about the efficacy of identity politics for advancing social justice and change. The problem in the 1980s and 1990s art debates was that many on the progressive side who opposed identity politics neglected to clearly explain the intellectual and ideological roots of their objection. The political scientist Adolph Reed Jr., a vocal critic of identity politics, has been arguing since 1979 that antiracist politics are concerned only with equitable distribution of opportunities or resources along racial lines without actually upsetting the reproduction of the social order.