Webster's Collegiate Dictionary defines affirmative action as "an active effort to improve the employment or education opportunities of members of minority groups and women." Some of the other areas of emphasis are age, religion, and ethnic origin. I feel the same as the authors of the Encyclopedia of the American Constitution, when they said these laws were brought about because,
In the judgment of a good many Americans, equality qua equality, even when conscientiously enforced with an even hand, would neither suffice to enable those previously deprived on racial grounds to realize the promises of equality of opportunity, nor would it atone, and provide redress, for the ravages wrought by two centuries of past discrimination. Consequently programs were established to go well beyond "mere" equality of opportunity and provide not only remedial but preferential compensatory action, especially in the worlds of EDUCATION and employment (Affirmative, Encyclopedia American 34).
However, even as early as 1978 the Supreme Court has made it a point to not support laws that provide for "reverse discrimination," which Webster's Collegiate Dictionary defines as "discrimination against whites or males as in employment or education." The Supreme Court stated that this isn't acceptable when it decided "reverse discrimination" is not acceptable legally or constitutionally (Affirmative, Encyclopedia American 35). I think what they mean by this is that, even though affirmative action is necessary, it should not be so harsh as to make it so the "majority"