Will the Supreme Court strike down what President Lyndon Johnson called “one of the most monumental laws in the entire history of American freedom”? That is the question before the justices on Wednesday, when they will hear a challenge to the constitutionality of a key provision of the Voting Rights Act. Enacted in 1965, it was designed to end, once and for all, the long, ugly history of racial discrimination in voting in America. The law, widely recognized as a remarkable success, was reauthorized in 2006 in a near-unanimous vote in Congress.

As Americans have come to recognize, however, the only votes that really matter are those of the justices of the Supreme Court. And there’s every reason to suspect that five justices will vote to strike down one of the law’s most important provisions.

That provision is known as “Section 5,” and it requires jurisdictions with a history of racial discrimination in voting to obtain the approval of the Department of Justice or a special court in Washington, D.C., before adopting any change in their voting rules. If one of these covered jurisdictions wants to move away from single-member districts to an at-large election, as several tried to do to reduce the voting strength of racial minorities, or change the voting hours, that change has to be “precleared” before going into effect.

This provision has been upheld in eight—yes, eight—previous Supreme Court decisions. Yet Shelby County, Ala., joined by conservative legal organizations, argues that preclearance is now unconstitutional because there’s no longer any significant efforts to discriminate in voting. As a result, the burden the law imposes is no longer justified, the county’s lawyers argue.

Preclearance isn’t the only way to combat discrimination, of course. Another provision of the law, which isn’t being challenged by Shelby County, outlaws any election procedures or rules that discriminate on the basis of race. The provision is valuable but suffers from the same problem that most civil rights laws suffer from: it’s costly and difficult to prove racial discrimination after the fact, and so much discrimination is never remedied.

Section 5’s innovation was to stop the discrimination before it occurs. By forcing jurisdictions—mostly, though not exclusively, in the South—to gain preclearance, the Voting Rights Act stops potentially discriminatory laws from being put into place to begin with. Shelby County is right that there’s much less evidence of racially discriminatory voting rules today. That may be because racism doesn’t exist in America anymore. Or it could be, as the Obama administration argues, because the prophylactic rule of Section 5 has prevented the racism that remains from taking the force of law.

A majority of justices is likely to disagree with the administration. In 2009, the court was presented with this same question. The justices ultimately ducked it, but Chief Justice John Roberts Jr. suggested in his opinion in that case that the time had come to reconsider preclearance. “Things have changed in the South,” he wrote.

Given the recent spate of restrictive voter ID laws enacted over the last few years, which disproportionately affect racial minority voters without the proper form of ID, one might wonder whether things have really changed so much. What else, though, would you expect from Roberts, whose view of race was clearly articulated in an affirmative action case: “The way to stop discrimination on the basis of race is to stop discriminating on the basis of race.” Pithy, yes; nuanced, not so much.

While it won’t surprise anyone if Roberts votes to strike down Section 5, the real irony will be if he is joined, as most court watchers expect he will be, by Justices Antonin Scalia and Clarence Thomas. Those two justices never stop extolling the virtues of originalism, the idea that the Constitution should be interpreted exclusively by the original intentions and public meaning of a provision when it was adopted. Yet there is wide agreement among legal historians that the men who wrote the Fifteenth Amendment after the Civil War to guarantee African-Americans the right to vote intended that provision to grant Congress broad authority to enact laws, like the Voting Rights Act, to protect the vote. They didn’t trust the courts to do that, given the Supreme Court’s decision a decade earlier in the already-notorious case of Dred Scott, which said blacks “had no rights which the white man was bound to respect.” They trusted Congress—and amended the Constitution to give Congress that power. (Along with other legal scholars, I filed a brief with the Supreme Court to that effect in the Shelby County case.)

Will the originalist justices follow the original meaning of the Fifteenth Amendment in Wednesday’s case? Don’t bet on it. If there’s one silver lining to seeing the preclearance provision invalidated, it is the revelation that for all to see that the purported originalists on the court are nothing of the sort.

CORRECTION: A previous version of this article incorrectly stated that the Supreme Court was faced with the preclearance question in 2006. It was in 2009.