orty-five years and a day after one Supreme Court justice opened the door to race-based college admissions in Regents of the University of California v. Bakke, six justices closed it. The Court has finally recognized that Justice Lewis Powell’s allowance of an “educational diversity” rationale has led to a system of racial discrimination that the Constitution prohibits.

Chief Justice John Roberts, writing for the majority, acknowledged what advocates of color blindness have long known: “Eliminating racial discrimination means eliminating all of it.” For far too long, colleges and universities have been given a blank check, under Bakke and its 2003 follow-up, Grutter v. University of Michigan, to use race and ethnicity to confer benefits on applicants from certain groups, while penalizing applicants from others. Such policies violate the principle of equal protection because, as Roberts put it, the Harvard and UNC programs at issue “lack sufficiently focused and measurable objectives warranting the use of race, unavoidably use race in a negative manner, involve racial stereotyping, and lack meaningful end points.”

The last bit bears repeating. Even if racial preferences could once have been justified by America’s sordid racial history—though the remedial rationale failed to gain a majority in Bakke—a sunsetting had to be contemplated to permit, even temporarily, such an extraconstitutional practice. The need for an expiration date is even stronger for such a flimsy rationale as educational diversity, which both supporters and opponents of race-conscious admissions have long recognized as a stand-in for other social-justice goals.