"I think that private universities such as Princeton should be free to engage in whatever kind of affirmative action they want."
That may be the blogger's opinion, but that is not the law of the land. In fact, higher education institutions are prohibited from discrimination on the basis of race,
http://www.ed.gov/policy/rights/guid/ocr/raceoverview.html
and one student who filed a complaint
http://www.ed.gov/about/offices/list/ocr/complaintprocess.ht...
against Princeton under that process found that his complaint was broadened into a compliance review, which still hasn't been resolved as of the last press report on the review.