Earlier this month, the Supreme Court heard oral arguments in Fisher v. Texas (again). The university and all its "diversity" supporters hope the Court buys the notion that preferences are all good and only help to improve the learning climate on campus. They hope it ignores the many arguments to the contrary, especially the "mismatch" probability -- i.e. that many of the supposed beneficiaries of preferences will do less well educationally at the "better" school they're admitted to.
In his December 9 Pope Center piece, UCLA law professor Rick Sander, who has done as much work on this as anyone, writes about the strong case that preferences create tangible harms for many students.