Actually, instead of "permanent" I should have used the word "fixed." That's what I mean by stratification -- i.e., that AA is helping ensure class positions in minority communities become fixed and is basically creating an AA aristocracy. A permanent minority upper middle class is a great thing, but a modern day aristocracy? Not so much...
I reach this conclusion for (mostly) 2 reasons:
1) The standard of living for poorer minorities is getting worse, not better, making it that much more difficult for them to move up in the world;
2) AA makes no pretention of even reaching out to disadvantaged minorities. As you said, it helps elite minorites become a part of elite white institutions.
But how is AA assuring that class distinctions in minority communities become fixed? It seems to me like the "fixed-ness" of class distinctions (i.e., lack of mobility) has nothing to do with AA and everything to do with the education/environment in poor communities (of all races) and in middle class communities of color. AA doesn't really affect this, since it is a policy that generally aids the elite minorities.
It seems to me like the lack of mobility in the US is a problem facing all kids who grow up poor, and AA doesn't affect it much at all. People often say that there should be a better system in place for bringing educational opportunities to poor kids. I agree. But AA isn't the reason that such a system doesn't exist. It doesn't exist because the majority of voters aren't in favor of programs that would shift resources from the wealthy to poor communities or poor people.
Certainly the lack of mobility is caused primarily by other factors, but since AA in no way helps less well-off minorities, I think it further augments this lack of mobility by failing to offer poorer minorities avenues of success (if they don't have a way out of their situation, how can they possibly esccape it?). Maybe I'm viewing it as a sort of zero-sum game (i.e., if it doesn't help poor minorities it hurts them). I don't think that AA has caused
social stratification, but one long term effect I think it will have is further social stratification (i.e., ensuring the elites remain where they are and, by implication, also ensuring the poor and middle class do the same).
I think it's a shame though, because the program was designed to correct years of racism and help those most harmed by it. Well, those living in areas most impacted by racism (inner cities and some poor rural communities) aren't getting a boost from AA. Instead, those equipped with the power to fight any discrimination they might face in their lives benefit from the program.
The solution (to which you alluded), is of course much more painful. We desperately need something new in place though...otherwise we'll never see the sort of racial equality those who enacted AA programs into law envisioned.