Affirmative action is an imperfect way to address discrimination. It served a useful during a time when legal precedent was being established. Now, if someone chooses to discriminate based on race, there's plenty of legal precedent. Back when affirmative action was more useful, there were many police depts., fire depts., construction crews, etc. that were all white. How do you correct for those types of inequities in the short term? If you weren't allowed to become a cop because of your race, it would be pyrhric victory to change the law and then continue to hire the sons and grandkids of firefighters who had inherited so many advantages. These are not easy problems of fairness to address.