Not with regard to racial preferences, but because the ABA has heavy-handedly sought to require librarians, writing instructors, and clinical faculty be granted tenure or tenure-like protections. I can certainly see the case for law schools choosing to give these faculty members tenure (assuming tenure is a good idea to begin with, which I'm not sure is true), but I don't see any reason why the ABA should be requiring every law school in the country to do so. Indeed, the real reason is likely (a) heavy lobbying from groups representing librarians, writing instructors, and clinical faculty; and (b) the ABA's general indifference to the costs it imposes on legal education. Actually, from the ABA's perspective, the more legal education costs, the better, because that way the cost of law school serves as a greater barrier to entry. There's no reason the Department of Education, which is deciding whether to continue using the ABA as the accrediting body for law schools for federal purposes, should endorse the ABA's rules. For that matter, there is no reason the ABA should be mandating how many classes are taught by full-time faculty as opposed to adjuncts, nor restricting the number of hours faculty may be required to teach.
Thanks to John Rosenberg for the pointer.