How "Black" is "Black"?

Roger Clegg publishes his otherwise-unpublished letter to the editor of the New York Times on the subject of racial classification. There have been some new studies out that show that the "wrong" blacks are benefiting from preferential admissions policies, and Roger puts in his two cents on how one should determine "blackness."

His comments are spot-on, IMO, and I would also add these examples to the pot. I have a good friend who considers herself "black." She has one "black" natural parent and one "white"natural parent, and was also adopted by "white" people. She comes from a northern Midwestern state and is culturally indistinguishable from people who live there, including valuing the pursuit of education. She's certainly proven that she's smart enough and dedicated enough to make it on her own. Her kids are blonde and blue-eyed; nothing about their appearance would lead you to suspect that in a former era they'd be considered "black". I also know a family who have adopted three children: one "white", one "black", and one half-and-half. The father is Irish and the mother is Hispanic. They are not raising their kids anywhere near the ghettoes of Los Angeles, Chicago, or New York City, and since they are both college educated, odds are their kids will be too. Their darker-skinned kids are just as likely as their lighter-skinned one.

So are these "black" people that I've described above really in need of affirmative action to get into college? They certainly aren't in the "target" group of "black" people that affirmative action is supposed to be helping. This classification-by-skin-color thing isn't really as straightforward as it would seem, is it?

UPDATE: Michael Williams has an excellent post on minorities in education.