Looking at this within the scope of "Affirmative Action" I think betrays a certain bias.
Race is certainly already a factor in society, the economy, business, and globalization (international students). In this context, if business schools did not include minority and international perspectives within their classes it would neccesarily mean a worse product.
So the problem is,..what happens when certain races have, on average, dramatically lower testing scores than their white or indian counterparts? At that point it becomes a judgement of whats more important between A) making sure every admitted student demonstrated to the same bar that he/she can intellectually handle the material or B) make sure the product (a b-school education) is as strong as possible with a diverse set of experiences and opinions. This is purely a business decision. With that in mind, the Supreme Court will not interfere with something it deems a legitimate business decision (unless the decision directly contradicts the constituition).