Several chapters in Stanley Fish's book There's No Such Thing As Free Speech: And It's a Good Thing, Too are devoted to a debate on affirmative action he and Dinesh D'Souza had back in the nineties. I'm not going to go into any detail, particularly because I didn't hear D'Souza's side of that conversation. Instead, thanks to reading these chapters, I think I can offer a diagnosis of why this issue has seemed so intractable.
Typically, those opposed to affirmative action prioritize Non-discriminatory Rules. Those in favor of affirmative action prioritize Equitable Situation. In an ideal society, it would be true that the rules are colorblind and there is little difference in the actual situation of historically dominant vs. historically oppressed races. But we don't live in that society.
What I'm hearing from affirmative action advocates is that colorblind rules don't — or don't quickly — result in equal opportunity when the pre-existing situation was askew. A much faster way to improve the situation is to allow the use of discriminatory rules in favor of the historically oppressed race.
What I'm hearing from opponents of affirmative action is that racial discrimination itself — not its effects — is the primary evil. If it's going to take a few more generations for, say, American blacks and whites to be similarly situated in society, so be it.
You can think of this as fair process vs. fair results in the context of unfair history. Which goal ought to be prioritized? The only way to answer that question would be to pick a third goal with something to say about the first two...and prioritize that. So instead of offering an answer to the affirmative action debate, I'm offering a way to understand it.