I do not believe your "nearly all," and you did not provide links, but I did find this:
http://community.seattletimes.nwsource.com/archive/?date=20041106&slug=colleges06
Tennessee State University, for instance, was at one point under court order to increase its non-black enrollment to 50 percent. The court eventually dropped that requirement, and the school has agreed to earmark $924,000 a year for scholarships to white students.
Heh. So "whites only" scholarships are consider permissible if and only if their primary purpose is not to help whites, but to prevent predominantly black colleges from losing federal funding or being sued into oblivion. I love it, you found the exception that proves the rule.
Private universities, such as Hampton in Virginia and Howard, face no court mandates to attract white students and generally have less diverse student bodies.At Howard (University), 1 percent, or about 100 of the 11,000 students are white. Those who do enroll are generally drawn by its academic reputation or its music and athletic programs.
Some people just don't value diversity.
I should make it clear that my point was to disagree with the original poster that "...there are scholarships only open to whites, to Norwegian descendants, to women, to rural students, etc.", as though scholarships primarily intended to benefit whites were commonplace and were generally tolerated in modern America. That is not true.
consider permissible > considered permissible