But there are a number of studies demonstrating how race & class impact things (when controlled for other factors) like teacher perception, grading, letters of recommendation, not to mention just the fact that if you are growing up in a black (or white) household that has $5 in wealth, you'll have less access to educational opportunity than the white (or black, albeit far more rarely) household with $200,000 in wealth.
We shouldn't seek to control for these factors?