I think Columbia tries to get minority representation proportional to the level of representation in the general population. So my GUESS is that, for example if 5% of the US is population of Who's, they'd loosely aim to hit 5% of Who's in the class. So let's assume the class is 100 persons, so there would probably be an approximate goal for 5 Who's per class. This means that out of the pool of Who applicants, the top 5 to 10 will be admitted depending on estimated yield to offers. You might see an array of LSAT and GPAs accepted, perhaps below the average for the school in general, in order to try and meet that goal of proportional representation of the minority group, but that range would be effected by the level of applicants they have to select from. I hope that makes sense.
(Sorry for the Dr. Seuss reference, I just saw Horton last week).