Which academically talented student deserves a preference in college admissions—the African American daughter of Harvard educated lawyers, or the African American son of a high school educated school security guard? The traditional answer of most liberal advocates of affirmative action is “both.” Affirmative action is about creating racially diverse campuses, or combating racial discrimination, which knows no economic bounds. Discussion of economic class is seen as a diversion from the underlying purpose of affirmative action to address racial inequality. In practice, however, saying affirmative action is about race, rather than class, has meant that privileged black applicants—people like Barack Obama’s daughters—consistently beat out disadvantaged black applicants, like Tony Jack, a student profiled in Sunday’s New York Times.

But cracks are beginning to appear in the reigning orthodoxy on affirmative action, and the cracks are coming not from conservatives, but from liberals. Senator Obama, like almost all elected Democrats, has been a strong supporter of race-based affirmative action, but he recently suggested an apparent shift in emphasis to helping low-income students of all races. On ABC's "This Week" show, George Stephanopoulos asked Obama, "you and your wife went to Harvard Law School . Got plenty of money, you're running for president. Why should your daughters when they go to college get affirmative action?"

In his response, Obama didn't take the question to a higher level of abstraction and talk generally about the importance of racial diversity; he stuck with the concrete facts. "I think that my daughters should probably be treated by any admissions officer as folks who are pretty advantaged..." Then, he went further, "I think that we should take into account white kids who have been disadvantaged and have grown up in poverty and shown themselves to have what it takes to succeed."

Interestingly, to the extent Obama justified continued preferences for African American students, he tied it to their parent’s educational status. "What we can say is that in our society race and class still intersect, that there are a lot of African American kids who are still struggling, that even those who are in the middle class may be first generation as opposed to fifth or sixth generation college attendees, and that we all have an interest in bringing as many people together to help build this country."

The problem with current race-based affirmative action policies at selective colleges is that they repeatedly tend not to benefit the first generation African American college students that Obama describes but rather those from more privileged backgrounds. At 19 selective colleges and universities studied by William Bowen in his book, Equity and Excellence in American Higher Education, 83.6% of underrepresented minority applicants had parents who were college-educated. (The whites were even more educated.)

Reporter Sara Rimer’s compelling story in The New York Times notes that Tony Jack, a low income African American student, was admitted to Amherst College because of an admissions preference based on class rather than race. With his 1200 SAT score, under traditional race-based affirmative action programs, Jack would have been beaten out by higher scoring blacks (and whites), the vast majority of whom are from privileged backgrounds. But Amherst College , under the leadership of president Anthony Marx, explicitly provides positive consideration not only to underrepresented minorities but also to low income students of all races who have overcome obstacles. The Amherst admissions director, Tom Parker, explains, “Tony Jack with his pure intelligence—had he been raised in Greenwich , he would have been a 1500 kid.”

Politically, Obama's emphasis on class before race is complicated. On the one hand, there is far more public support for providing a leg up in college admissions to low income students than to minority students. Polls taken in 2003 by the Los Angeles Times and Newsweek found about 2:1 support for providing a preference to low income students, as compared with 2:1 opposition to providing preferences based on race. The public wants to reward Tony Jack, whose mother is a single parent making $26,000 a year, not Obama’s kids, who will grow up with tremendous advantages.

On the other hand, there are powerful organizations in the United States mobilized in support of minority groups and women—the traditional beneficiaries of affirmative action—but no similar organizations for the poor and economically disadvantaged per se. While titans of the labor movement like the late Albert Shanker, president of the American Federation of Teachers, advocated preferences based on class rather than race, today most of organized labor has fallen in line on racial preferences. Even the AFT supported the University of Michigan 's use of race in the Supreme Court a few years ago.

In March 1995, when President Bill Clinton announced at a press conference that he wanted to shift to class-based affirmative action programs "because they work better and have a bigger impact and generate broader [public] support," he faced a political firestorm. Jesse Jackson threatened to run for president and Clinton commissioned a review of affirmative action programs which allowed him to eventually back away from substituting class for race.

Ultimately, however, the logic of class-based affirmative action is so powerful that even defenders of race-based plans often inadvertently strengthen the case for using class. Writing in the Washington Post, for example, Eugene Robinson recently argued for taking race into account in part because discrimination means that "Minority students are disproportionately disadvantaged by having to attend substandard primary and secondary schools. Their parents are less likely to have attended college and thus may not be familiar with all the things parents have to do to make their children competitive when it comes to college admissions."

These things are all true, which is why minority students will disproportionately benefit from class-based affirmative action. But not all minority students attend substandard schools or have parents lacking a college degree, so why not target preferences precisely at those children (minority or white) who actually attend lousy schools and whose parents have less education?

Robinson correctly notes that racism continues to plague even more affluent people of color. But the Supreme Court does not allow preferences as a remedy for societal discrimination. Moreover, class-based preferences can effectively remedy most of the effects of racial discrimination. For example, discrimination in housing means that blacks are more likely to live in neighborhoods were housing appreciates at slower levels, and results in lower levels of wealth. (Black wealth is 1/10 of white wealth, a much greater differential than the gap in income.) Having less wealth is a disadvantage to students, so why not count that in the admissions process? And if an individual student was the victim of discrimination by a teacher, count that too at an individual level, rather than providing a blanket preference based on skin color.

While many of my fellow liberals recoil at the notion of class-based affirmative action, the idea has noble roots, going straight back to Martin Luther King Jr. King knew there was a need to compensate for past discrimination but also that the colorblind principle he annunciated could not be casually dismissed. In his 1964 book, Why We Can't Wait, King made the classic argument for taking affirmative steps to address our nation's history. He wrote, "It is obvious that if a man is entered at the starting line in a race three hundred years after another man, the first would have to perform some impossible feat in order to catch up to his fellow man." But instead of proposing a plan of preferences for blacks, he proposed a "Bill of Rights for the Disadvantaged." King said, "It is a simple matter of justice that America , in dealing creatively with the task of raising the Negro from backwardness, should also be rescuing a large stratum of the forgotten white poor."

Today, race-based preferences are in trouble. An anti-affirmative action ballot initiative passed easily in Michigan last year and similar initiatives are planned for several states in 2008. Meanwhile, a new conservative Supreme Court majority has set its sights on curtailing the use of race in assigning students in elementary and secondary education. It is time for fresh thinking on the difficult issue of affirmative action. Barack Obama understands that current race based policies leave too many talented students, like Tony Jack, behind. Following in the footsteps of Martin Luther King, Obama may be edging towards a transformative role.

Richard D. Kahlenberg is a senior fellow at The Century Foundation. Portions of this article appeared previously in the Washington Post.