Affirmative action has emerged as one of the nation's hottest political issues. Supporters say the policy has opened opportunities for women and minorities and is still needed to offset discrimination. Critics say it has evolved into quotas, preferences and set-asides that amount to reverse discrimination against white males. Republican lawmakers and presidential hopefuls want to end affirmative action; President Clinton has called for an internal review of affirmative action policies in scores of federal programs. In California, a proposed ballot initiative would outlaw race- and gender-based policies in public education, public employment and government contracting. Polls show Americans favor affirmative action but oppose quotas and preferences. The issue is likely to simmer through the 1996 elections.