In 1978, the Supreme Court held that the use of affirmative action in college admissions was constitutional. Conservatives have long sought to overrule this decision, and in 2003 the Supreme Court struck down some, but not all, university affirmative action programs. Affirmative action survived another brush with the court in 2013, when the Roberts court surprisingly remanded a case, Fisher v. University of Texas, brought by a white student who claimed that affirmative action had resulted in discrimination against her.

Now, the same group behind Fisher, the Project on Fair Representation, is back with two new lawsuits that seek to eliminate the use of affirmative action in university admissions entirely. Given the current composition of the Supreme Court, the lawsuits may well succeed if they reach that level. But such a ruling would be a historical travesty and a mistake.

The two lawsuits challenge the admissions policies of the University of North Carolina at Chapel Hill and Harvard University, arguing that they discriminate against Asian-American applicants, a group that often finds itself at a disadvantage when it comes to race-based quotas. The suit against UNC alleges that the university is in violation of the Equal Protection Clause of the Fourteenth Amendment. Because Harvard is a private institution, however, it is not bound by the restrictions of the Fourteenth Amendment. Instead, Harvard is being sued under Title VI of the Civil Rights Act, which has generally been interpreted as imposing similar obligations on universities that receive federal funds.

The complaints were brought by a new group called Students for Fair Admissions that is affiliated with the Project on Fair Representation. Unlike Fisher, they attempt to appeal to moderates both inside and outside the federal judiciary by agreeing that racial diversity is a worthy goal for universities, but arguing that race-neutral measures would be adequate to achieve diversity. Universities, they argue, could ensure diversity through such measures as taking socioeconomic status into account and ending legacy and early admissions.

As a policy matter, we should be skeptical of these claims. Class-based affirmative action can partially make up for ending race-based affirmative action, but not entirely. The legacy of racial discrimination remains very important, and class is not a sufficient proxy for race in the contemporary United States. As Slate's Jamelle Bouie has observed, "Blacks and whites (and to a lesser extent, Latinos) of similar economic status live in dramatically different environments." It is certainly appropriate for universities to take this into account.

Admittedly, the plaintiffs may have a point with Harvard in particular. The university gets so many overqualified applicants, and has such a wealth of resources, that race-neutral measures could probably produce a similarly diverse student body. Whether this would be true at schools with less money and fewer top students to choose from is far more questionable. Ending affirmative action in Michigan, for example, caused a significant decline in enrollments by African-American and Latino students.

In addition, the argument that ending affirmative action could be made up for in part or in whole by eliminating legacy admissions and increasing aid to poor students seems naïve. There is little reason to believe that the vast majority of schools that lack Harvard's huge endowment will drop legacy admissions (and the fundraising potential that comes with them), or will be able to offer many more scholarships to poor students.

It may well be salutary for universities to experiment with different means of achieving a diverse student body. At least some may find formally race-neutral means that work well. What these lawsuits seek, however, is not merely to encourage experimentation but to forbid taking race into account altogether. That is a different story.

On this question, the argument that affirmative action is categorically illegal under the Fourteenth Amendment or the Civil Rights Act is simply wrong. Neither text explicitly forbids affirmative action. And it is illogical — not to mention ahistorical — to argue that racial classifications intended to promote diversity are the legal equivalent of racial classifications that sought to uphold a white supremacist caste system. Opponents of affirmative action are hardly underrepresented in the ordinary political process, and this is where they should make their case.

That being said, it does not follow that every affirmative action program is constitutional. If the litigants are able to prove their allegation that Harvard had a rigid cap on the number of Asian-American it admits, comparable to its infamous limits on Jewish students for much of the 20th century, it would plausibly be guilty of the kind of invidious discrimination that the Civil Rights Act forbids.

But even if the court finds that this particular program is illegal, it would be unwise to forbid all affirmative action programs. Race still tragically matters in America, and universities should not be required by the federal judiciary to ignore this fact.