The Supreme Court’s decision in Louisiana v. Callais, issued on Wednesday, April 29, 2026, needs to be understood in a few different contexts.

First, it needs to be remembered that in the South, the color line and the party line come very close to being the same thing: Whites tend to vote Republican and non-whites tend to vote Democratic.

Second, the Supreme Court ruled in Rucho v. Common Cause (2019) that partisan gerrymandering–the drawing of district lines to give one political party disproportionate strength in either a state legislature or a state’s delegation to the House of Representatives–is not judiciable by the federal courts; that is, the federal courts can’t interfere with it. Racial gerrymandering is a different story. Federal courts can still step in when district lines have been drawn to discriminate against a racial group, to weaken a racial group’s influence in the political system.

Third background point: In the 2023 case of Allen v. Milligan, not one but two of the conservative justices, Chief Justice John Roberts and Justice Brett Kavanaugh, surprised many people by voting with the liberal justices to uphold a lower federal court ruling requiring Alabama to redraw its map of congressional districts. The decision applied a 1982 amendment to the Voting Rights Act, as supported by the 1986 Supreme Court precedent Thornberg v. Gingles, to say that there needed to be one more Black-majority congressional district. The point was not that there had been any intentional racial gerrymandering, but merely that it was possible to draw a map with an additional Black-majority district without any wildly contorted shapes, that would give the Black population more proportionate influence with their votes, and that the lower court was right in requiring the state to do so.

Given that decision, the state of Louisiana figured that it had better redraw its own map to create another Black-majority district. But they wanted to do it in a way that would not jeopardize the seat of with house Speaker Mike Johnson or Representative Julia Letlow. Thus, the way they drew the map did involve a little bit of contortion. That was the rub: It made it possible for Louisiana whites–or, as the challengers called themselves, “non-African-Americans”–to claim that they were victims of a racial gerrymander against them. And this brought about the case of Louisiana v. Callais.

Most Supreme Court cases are wrapped up within one year, but in this instance, the Court heard arguments during its 2024-25 season and continued it into 2025-26. The first time around, the state was defending its map; in the re-argument, the state had switched sides and was teamed up with the “non-African-Americans” to oppose it. The Court, meanwhile, had asked for arguments as to whether the creation of that new Black-majority district violated the 14th and 15th Amendment.

In the final ruling, written by Justice Samuel Alito (one of the ultra-conservatives on the Court), the Court decided that the new map did indeed constitute an unfair racial discrimination–that is, discrimination against the “non-African-Americans.” The decision did not strike down Section 2 of the Voting Rights Act as amended in 1982, nor did it exactly reverse Thornberg v. Gingles. It did, however, say two key things that are going to make a difference in future maps and future cases. First, it said that Section 2 only applies if the racial gerrymandering can be shown to be intentional. Second, it made clear that partisan gerrymandering–drawing the lines to favor a political party–is perfectly all right and should not be interfered with even when a map has to be redrawn to correct a racial gerrymander.

The ruling has all six Republican appointees (Alito, Roberts, Thomas, Gorsuch, Kavanaugh, Barrett) in the majority and all three Democratic appointees (Kagan, Sotomayor, Jackson) in dissent. Elena Kagan, in her dissenting opinion, expressed regret about the 2019 decision that gave a green light to partisan gerrymandering, and about this decision that she claimed made use of that ruling to make it harder for minority voters to claim discrimination: “Under the majority’s new test…a plaintiff will have to show—contrary to Section 2’s clear text and design—that the legislators were ‘motivated by a discriminatory purpose.’ … And that, as Section 2’s drafters knew, is well-nigh impossible.”

Because the color line and the party line in the South come so close to being the same thing, it was hard enough to prove racial gerrymandering as opposed to mere partisan gerrymandering already. But now this ruling puts a heavier burden on those who want to claim that there’s been an unfair racial gerrymander at the expense of non-white political strength, and it reaffirms that partisan gerrymandering is perfectly excellent and salutary.

Many experts are of the opinion that this ruling is going to open the floodgates to a lot of redistricting, at the expense of non-white voting strength in the South and, thus, at the expense of Democratic voting strength, making it harder for the Democrats to have a majority in the House of Representatives for the long run. How right they are remains to be seen; it will take at least a few years to know. It isn’t likely to have a sweeping effect on this year’s midterm elections, but it is already having an effect in Louisiana: Primary elections are suspended until the map can be redrawn, surely eliminating that Black-majority district that the 2023 map had created.

Write-up on the ruling at Scotusblog, April 29, 2026

The  ruling itself, including the dissent