that's why representation matters. it's because the proportion is LS and the proportion in the general population are different. in a perfect world, you'd probably have diversity match the general population, such that 50% of the general population and the LS student population would be white, 5% of both would be asian, etc. it'd be a perfect microcosm. it doesn't work that way in real life, but AA attempts to get closer to that ideal.
I don't think a matched ratio of % minority population to % minority lawyers would necessarily equal the perfect system. And as long as we're talking about ideals, for me, the ideal is not to have URMs or AA because there is no longer any social need for it.
I don't think there's anything wrong with making sure any given group is represented, but there are factors beyond race.
In addition, I personally don't think it makes too much sense turning away overrepresented minorities if they are good candidates simply because we've reached our population quota for them. Of course, a perfect balance is always hard to obtain.