I was surprised at first at how complicated the whole question was. Well, not really. Remember that we are after unconscious discrimination, too, so you can't believe a person even when he thinks he is being honest. There are thousands of school districts in this country, and I can find a good argument in one that another is not doing what it should be doing. There is no objective school to be cited.
All cases differ.
All school histories differ. In order to make sure everybody is ignoring race you have to get into his or her mind. If you are looking for illegal immigrants on the Mexican border, you will save a lot of money if you ignore blond people with Germanic accents. They are perfectly correct. You ARE discriminating.