...but here's the issue: you posit that the racial complexion of DK/YK is the consequence of racial bias on the part of the leadership and/or user universe. I'm counter-theorizing that this stems from the negative self-selection that could arise from the ideological nature of the site. Your anecdote buttresses my theory, not yours.

I'd suggest it's time to widen your explanatory model to include my rather valid observations, namely that there are some reasons inherent in the black community for its under-representation at DKos. That would have the added charm of intellectual honesty.