If these URM's are "less qualified", it sure doesn't show when they get into the field. In fact, statistics are showing the exact opposite: they thrive! Richard Sander would have you believe that URM attrition from BigLaw firms is ultimate vindication of the anti-AA position, when, in reality, URM's at prestigious firms often perform so well that they are poached into more satisfying in-house corporate positions by headhunters working for corporate clients who patronize the top firms, many often doubling their firm salaries.
URM's leave BigLaw and other prestigious firms not because they cannot cut the mustard, but because they can. And the racial politics that persist in those environments make it an easy decision to do so.
And I still have a problem with Whites saying someone is "less qualified" for law school or the profession when the best data availabnle shows that the people with the best grades and test scores often make terrible lawyers. Did you see how Erin Brockovich did circles around her Ivy League counterpart? those clients didn't even want that lady back in their homes. She had no people skills, and that made her a poor lawyer. Boalt is not spending every breath to come up with a better law admissions test for no reason. All of the top schools (the ones admitting students with the best numbers and gaming the rankings) know that it's BS.
GPA/LSAT is about as accurate an indicator of potential for law practice as athletic ability is for success in pro sports. There are just too many intangibles left unexplained: staying injury free, tenacity, coachability, persistence, work ethic, luck, ability to work with others, etc. Having skills is a good start, but it doesn't predict much.
Can you direct us to the data? As much as I like Erin Brokovich, my intellectual side craves more persuasive empirics. You make two bold claims;
1 - The statistics by Richard Sander are wrong because blacks are poached by other firms/in-house;
2 - Best data available shows that the people with the best grades and test scores often make terrible lawyers
I do like your athletic ability analogy. I think it is pretty accurate. The LSAT would be the NFL scouting combine and GPA is college stats? I like it.