The constitution prohibits the enactment of laws, which make acts committed before the laws in question were passed punishable as crimes. ex post facto actus reus corpus delicti stare decisis

affirmative action refers to the policies that take gender, race, or ethnicity into account in order to promote equal opportunity.

employers subject to title vii are prohibited from taking race or sex into account in any employment decisions. aa is a penalty for having any job group substantially statistically "underutilized" in any race or either sex. the employer must take steps to eliminate the underutilization, then stop, ending its aa efforts