Affirmative Action, in general, is a good concept. However, Affirmative Action based on race is not for these two important reasons:
1) Race is not well-defined casually or biologically.
2) While people of minority races are statistically more likely to get the short end of the stick, educationally, it is not race that causes it.
What we really need is Affirmative Action based on socio-economic status or household income. This will be "color-blind" while still generally helping African-Americans and Hispanic-Americans more often than Caucasian-Americans. Being Black doesn't make it harder to succeed in school, being poor and hungry does. Sure, there is a correlation to race, but the root cause is poverty. Moreover, this helps (the often forgotten minority of) rural Appalachian White people just as much as urban Detroit Black people.