i'm pretty sure the argument for affirmative action is to benefit racial groups that are inherently "disadvantaged" due to their economic status preventing them from getting as good of an education as they possible could have, which is all nice and dandy in theory and I do agree that those who are disadvantaged should have some form of compensation.
In reality though, (at least from what i've seen) AA just promotes racial animosity and the feeling that you're not actually competing with other applicants but you just need to be better than "the next asian" (replace your own race here). Obviously my viewpoint is biased as fuck and is completely anecdotal, I'd just like to get my thoughts out there.
not to mention that if you were of a race that is seen as traditionally benefiting from affirmative action and you were a qualified applicant, some people will completely undermine your accomplishment because of your race. I personally knew a Mexican-American individual who was perhaps one of the most intelligent people I've ever met, and yet a lot of people belittle her accomplishments by saying things like "oh she only got in/got that job because she's ______" which is probably unbelievably shitty for her.