There is a principled case to be made against affirmative action. But it's not the one President Bush articulated in announcing his administration's intention to intervene before the Supreme Court in opposition to the University of Michigan's affirmative action plan.

You could make a case for true race-blindness. You could say that every applicant to college, every applicant to law school -- every person in society -- should be judged on the basis of his or her character, talents and potential. No one thinks or behaves in a certain way simply because he or she is black or white, this argument would go; therefore "racial diversity" in admissions or hiring is not a noble goal but an offensive rationalization of stereotyping. If race doesn't matter in judging a person, and if the admissions process is truly free of bias, then society shouldn't care whether a University of Michigan law school class is 5 percent black or 50 percent. We shouldn't even keep count.

That would be a principled argument, albeit wrong because it would be totally divorced from American reality. But it's not Bush's argument. On the contrary, he embraces racial consciousness: "I strongly support diversity of all kinds," he said last week, "including racial diversity in higher education."

Setting aside the tantalizing possibilities in the phrase "diversity of all kinds," the question is: Why? Why do colleges need more black or Hispanic students, as opposed to simply the most qualified people available? Why should we not be satisfied, as Bush says he is not, "with the current numbers of minorities on American college campuses"?

Because, the president explains, "a college education should teach respect and understanding and goodwill. And these values are strengthened when students live and learn with people from many backgrounds." And -- by implication -- one factor that is important in a student's background is race.

This may seem too obvious -- Gee, race still matters! -- to restate. It's true that no individual's reactions or philosophy are determined solely by race, or by any other single factor. But Supreme Court Justice Clarence Thomas can talk from the bench about cross-burning in a way that no white justice can. Collectively, statistically, blacks and whites in this country see the world differently. "Racial prejudice is a reality in America," Bush says (though apparently, he must have concluded, not in college admissions). He accepts, in other words, the basic rationale that most college presidents now offer for affirmative action: that racial diversity enhances everyone's education.

So there is something dishonest about the president's solution: "race-neutral admissions policies" that have the effect of increasing minority presence on campus. Race matters, he says; we should strive to admit more blacks and Hispanics; but we should pretend that we're not doing so.

The let's-pretend-it's-not-affirmative-action program that Bush knows best is in Texas, where, after federal judges ruled out racial preference in public university admissions, the state legislature devised the "10 percent rule." By law, all high school seniors who graduate in the top tenth of their class may attend any University of Texas campus, including the flagship school in Austin.

The beauty of the plan, at least in theory, is that it gives a leg up to students in every economically disadvantaged school, regardless of race, which should ease the stigma that some black and Hispanic students say affirmative action confers. Early experience also suggests that high performers, even from bad high schools, possess some quality that serves them well in college; the top-10-percent students outperform other students with higher SAT scores.

But by Bush's standard, the program isn't working all that well. Only 3.4 percent of Austin's freshman class last fall was African American. And the university did that well only because it established a comprehensive outreach program to 70 predominantly black and Hispanic high schools, offering tuition help, counseling and other inducements. It did that well, in other words, only because it returned to affirmative action by another name.

What's more, the top-10 plan works only because, and as long as, schools and communities remain racially segregated. And it is obviously impractical for smaller schools and private universities.

So what do you gain from the pretense? Bush wants credit for accepting racial diversity as a goal. But he would deny most schools any honest means to achieve that goal.