It's unfortunate that those who profess to abhor identity politics seem unable to see or talk about anything else when someone other than a white male is nominated to the Supreme Court. Even those who try to express their reservations in measured terms end up saying odd things along the lines of "We want to give her a chance to show that she can be an impartial judge, setting aside her identity as a Puerto Rican woman." Yet, when Roberts and Alito and Breyer and Souter were being confirmed, these same people never thought to question whether those men could set aside their identity as white men. A member of a minority group is presumed to be partial to their own group, while white men are presumed to be impartial.
White men are also given full credit for their own accomplishments, whereas the accomplishments of a minority are always suspect. People are thinking she's probably not as smart as her peers, but was advanced by affirmative action. In the discussions about Sotomayor, you can hear people raising questions about her intelligence and her jurisprudence that were never raised about Roberts or Alito. With the men, there were questions about their views, about their judicial philosophy, but their reputation for intelligence and for being top in their field was taken as a given. So why, when it's a Latina rather than a white guy, are so many asking "is she really intelligent? is she really excellent?" Personally, I don't have to look far to satisfy myself on those counts. While a policy of minority preference could possibly have been a contributory (but not decisive) factor into getting her accepted to Princeton and to Yale Law, there was no such factor in her graduating summa cum laude or becoming editor of the Yale Law Review. Those are only achieved through formidable intelligence and a lot of hard work. (Cue John Houseman: She got those the old fashioned way. She earned them.)