The rational basis test is used most of the time. Under it, courts usually uphold governmental actions. The next-highest level of examination is intermediate. It's tougher than the rational-basis test. Many due process cases are judged by this standard.
Officials often lose when judges strictly scrutinize their actions.
Traditionally, courts applied strict scrutiny chiefly to official invasions of first amendment rights. These include freedom of speech, of the press and of religion. Now the super-tough test applies to affirmative action in all its various forms. The Adarand Court did not throw out affirmative action, although Justices Antonin Scalia and Clarence Thomas wanted to. Sandra Day O'Connor, who wrote the majority opinion, insisted it won't be fatal for all affirmative-action programs.