I think anyone who finds issue with Sotomayor's comment regarding being Puerto Rican and her experiences has probably never been to any of the 5 boroughs of NYC, particularly the Bronx. Yes, anyone born here is a United States Citizen (and, so are those born in Puerto Rico; they can travel back and forth without visas or green cards and they can vote in our primaries, but not the general election. They are also represented in Congress with non-voting powers)
So you can see that it is not so black and white.
The boroughs, like the Bronx, have pockets of different ethnics groups very unlike any other parts of the Country, so socially, people do associate themselves ethnically. Here, experiences will be vastly different than anyone else in this Country because of this exposure, as compared to a white Princeton graduate from say the South.
I can say all this from very personal experience. I've lived in the Bronx, grew up in Yonkers, which borders Riverdale/Bronx and to boot, my father was born in Puerto Rico (his Father was French, but lived his life and died in PR) and frequently took me to the Bronx to eat Puerto Rican fare that took too much time for him to cook, that I enjoyed and grew up with.
A person may be of a certain descent, be born here, but have not experienced what life is like from the culture they descended from, at least not on a daily basis. Here, in the boroughs, this is commonplace, which is why Puerto Ricans will associate themselves, born here, or any Latin country, with being Puerto Rican. (if one or more of their parents are Puerto Rican)
I knew exactly what Sotomayer meant by her comment. I have almost walked in her exact footsteps. I was accepted to Princeton, went to visit friends who attended, but their experiences were vastly different than mine. I was able to travel in those circles, but did not come from a moneyed background, far from it; nor could I sympathize with some of their worries, which at times seemed trivial to me. It didn't mean I didn't empathize with their situations because I was exposed to it. It didn't mean I was biased either became we came from different backgrounds.
She'll add a very different viewpoint from the Bench, IMHO.