For decades, conservative justices have made a specific point to support many of their rulings on race: They insist that the Constitution is entirely “colorblind,” prohibiting any consideration of race under all circumstances. During oral arguments in Merrill v. Milligan on Tuesday, a case they will attempt to use to eradicate what remains of the Voting Rights Act, they advanced this theory once again. This time, however, Justice Ketanji Brown Jackson refused to cede ground to their revisionist history. In a series of extraordinary exchanges with Alabama Solicitor General Edmund LaCour, Jackson explained that the entire point of the 13th, 14th, and 15th Amendments was to provide equal opportunity for formerly enslaved people, using color-conscious remedies whenever necessary to put them on the same plane as whites. It was a masterclass in progressive originalism that illustrated exactly why Jackson is such a crucial addition to this ultra-conservative court.

Merrill involves a challenge to Alabama’s new congressional districts, which constitute a flagrant racial gerrymander: Republican lawmakers packed most Black residents into one sprawling district, then gave white voters control over the remaining six districts. As a result, Black voters control just 14 percent of congressional districts despite making up nearly a third of the state’s population.

The Voting Rights Act was designed to outlaw this kind of dilution of racial minorities’ voting power. Indeed, Congress amended the law in 1982 to make it crystal clear that race-based vote dilution is impermissible. It was no surprise, then, that a three-judge district court (including two Donald Trump nominees) threw out Alabama’s new map in January as a violation of the VRA. Its 225-page opinion painstakingly explained that the state had an obligation to create a second district in which Black voters had a real shot at electing their preferred representative. But the Supreme Court froze that ruling in February by a 5–4 vote, and heard arguments Tuesday.

Alabama’s argument is that the law—as interpreted by the lower court—violates the 14th Amendment’s equal protection clause. Even though Section 2 of the VRA compels states to ensure that the political process is “equally open to participation” by all races, which obviously requires the use of race to guarantee equality, the state is arguing that any consideration of race in redistricting violates residents’ constitutional rights—even if race is used to safeguard Black voters’ political power. The goal is to get the Court to say that the VRA cannot require the creation of districts in which racial minorities make up a majority, because such race-conscious line-drawing would infringe on equal protection.

Justice Sonia Sotomayor has contested this race-blind theory of equal protection in the past, but on Tuesday, she let the newest justice offer Alabama a history lesson. And Jackson was having none of it. “I don’t think we can assume that just because race is taken into account, that that necessarily creates an equal protection problem,” Jackson told the Alabama solicitor general. “I understood that we looked at the history and traditions of the constitution, at what the Framers and the Founders thought about. And when I drill down to that level of analysis, it became clear to me that the Framers themselves adopted the equal protection clause, the 14th, the 15th Amendment, in a race-conscious way. That we were, in fact, trying to ensure that people who had been discriminated against, the Freedman, during the Reconstruction period, were actually brought equal to everyone else in society.”

The justice then went deeper, citing the Report of the Joint Committee on Reconstruction from 1866, produced by the lawmakers who drafted the 14th Amendment. “That report says that the entire point of the amendment was to secure rights of the freed former slaves,” Jackson explained. She continued: “The legislator who introduced that amendment said that ‘unless the Constitution should restrain them, those states will all, I fear, keep up this discrimination and crush to death the hated Freedman.’ That’s not a race-neutral or race-blind idea in terms of the remedy.”

Jackson went on to note that one purpose of the 14th Amendment was to provide a constitutional foundation to the Civil Rights Act of 1866, which “specifically stated that citizens would have the same civil rights as enjoyed by white citizens. That’s the point of that act, to ensure that the other citizens, the Black citizens, would have the same as the white citizens.”

“With that background,” she told Alabama’s solicitor general, “I’m trying to understand your position [on] Section 2, which by its plain text is doing that same thing. It’s saying: You need to identify people in this community who have less opportunity and less ability to participate and ensure that that’s remedied. It’s a race-conscious effort, as you have indicated. I’m trying to understand why that violates the 14th amendment given the history and background of the 14th Amendment.”

Jackson is plainly correct: The Framers of the 14th Amendment (which guarantees equal protection) and 15th Amendment (which bars race-based voting discrimination) explicitly supported race-conscious remedies to civil rights violations. They intended the post-Civil War amendments to guarantee equal opportunity to Black citizens, combatting “deep rooted prejudice of the white race” against Black Americans to help them secure a “just and constitutional position.” As legal historians have persuasively explained, the Framers readily took race into account when necessary to redress past discrimination.

So much about Alabama’s Black communities today—their location within the region, their economic hardships, their struggles to exercise equal political power—is a result of past discrimination. Congress wanted the VRA to ensure that these communities could finally participate equally in the political process, through race-conscious redistricting if necessary. Alabama Republicans want the opposite; they seek to impose a devastating racial gerrymander—under the theory that protecting Black citizens’ voting power would violate the 14th Amendment’s equal protection clause.

This theory is as perverse as it is ahistorical. Jackson refused to let it go unrebutted. There’s little doubt that the conservative justices will still outvote her here, and in the upcoming affirmative action cases, where Republican lawyers are using an anti-originalist theory to abolish race-conscious admissions. It is distressing to see self-identified originalists mangle history to further their own policy goals. At least Jackson won’t let them do it without a fight.