The reason people supposedly separate the social from the economic in the race conversation (but just rewind and replay this argument for feminism as well) is that "a poor white man can attend a rich white man's party while a rich black man is excluded".
The reason is supposedly *just* because people with darker skin tones are psychologically not tolerated and excluded. Racism is not learned and cultural behavior, but some instinctive behavior with origins in the amygdala. Racism can only be addressed through acknowledgement of that innate bias.
The people who hold economic views about racism also believe that stereotypes build up over time, through history, experience, and cultural practice. The police find lots of crime occurring in poor black neighborhoods because of poverty: they start to associate black people with crime: voila, racial profiling. However, the poverty in those neighborhoods, can be sourced further back to original economic injustices: employment discrimination, housing policy, even all the way back to slavery. Learned associations build up, children learn prejudices from their parents.
It seems to me that the high level, meta discussions of racism have evolved to the point where the persuasive arguments usually involve a combination of the two (nature/nurture).
And the standard views on DU also seem to involve a combination of the social/economic for both racism and feminism.
That's why I assumed that when people try to split off the social from the economic that it's just a rather awkward political maneuver that assumes more unity can be found in the "social", and abandoning the "economic" will just trim the "wing".
I find it strange that some people seem to take it farther than a political maneuver and seem to be vesting some personal commitment in "social" vs. "economic".
The whole thing makes me queasy, because on the feminism side, I associate focusing on the social with upper class, white women getting their policy moves made, while separating themselves from poor women of color. That's what focusing on the social meant in the 1980s, at least. It does freak me out when I see it again here, even if the connotation is now something different.