The Supreme Court is set to rule on the Trump administration’s addition of a citizenship question to the 2020 census as soon as Wednesday. But if the five conservative justices uphold the citizenship question, as appeared the likely outcome following oral arguments, a federal appeals court ruled on Tuesday that a judge may block the question again over new evidence that further proves the question’s illegality.

This last-minute development centers around information found on the files of Thomas Hofeller, the GOP’s former gerrymandering guru. When he died last year, Hofeller left behind a trove of materials that his estranged daughter turned over to voting rights advocates. Among other things, these files suggested that Justice Department officials worked with Hofeller to devise a pretextual justification for the census citizenship question, asserting that it would aid enforcement of the Voting Rights Act. This pretext was meant to conceal the real reason for the question: It could, Hofeller explained, substantially reduce the voting power of Democrats and Hispanics while boosting that of “Republicans and non-Hispanic Whites.”

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The new materials also provide a direct link between Hofeller—who, evidence shows, devised the false justification—and the Census Bureau. They seem to further demonstrate that Commerce Secretary Wilbur Ross lied when he provided his rationale for the insertion of a citizenship question into the 2020 census. Plaintiffs argued that this evidence ties Hofeller’s work, which lays out the racist impact of a citizenship question, directly to the Trump administration. By doing so, they claim, it proves the question is motivated by unlawful animus.

Responding to these bombshells, U.S. District Judge George Hazel reopened the case on Monday. Hazel had initially determined that the question’s addition violated the Administrative Procedure Act and the Constitution’s enumeration clause but did not find proof of discriminatory intent in violation of equal protection. He wrote on Monday that the new evidence, by contrast, “potentially connects the dots between a discriminatory purpose—diluting Hispanics’ political power—and Secretary Ross’s decision.” It is, he wrote, “becoming difficult to avoid seeing that which is increasingly clear. As more puzzle pieces are placed on the mat, a disturbing picture of the decisionmakers’ motives takes shape.” And on Tuesday, the U.S. Court of Appeals for the 4th Circuit ruled that Hazel may examine the new evidence and decide whether it proves the question is illegally discriminatory.

There is a strong possibility that SCOTUS will authorize the citizenship question this week and Hazel will block it on different grounds shortly thereafter.

The Supreme Court, of course, is currently assessing the legality of the question and will almost certainly issue a ruling later this week. But the court is set to resolve just two disputes: whether the citizenship question was added in an “arbitrary and capricious” manner under the Administrative Procedure Act, and whether it will impermissibly warp results in violation of the Constitution’s enumeration clause. It is not set to decide whether the question infringes upon equal protection or constitutes an unlawful conspiracy to suppress civil rights.

If Hazel decides that the question does run afoul of equal protection and civil rights, he can block the question again. In fact, 4th Circuit Judge James A. Wynn wrote a concurrence to Tuesday’s decision advising Hazel to block the question preemptively while he contemplates his ruling. (Wynn speculated that the government will otherwise attempt to print the census forms quickly and claim the case is mooted.) There is a strong possibility, then, that SCOTUS will authorize the question this week and Hazel will block it on different grounds shortly thereafter.

If that happens, the Justice Department will surely ask the 4th Circuit to unfreeze the question. Based on Tuesday’s ruling, it will probably refuse, forcing the DOJ to ask SCOTUS to stay Hazel’s injunction. If the Supreme Court has already upheld the citizenship question on different grounds, it seems likely to grant that stay. It could potentially even deny further discovery into clear evidence that administration officials lied to the courts to cover up the discriminatory animus behind the question—which is what prevented Hazel from ruling on the equal protection issue in the first place. Such a decision would give rise to an even stronger impression that the Supreme Court’s conservative majority is simply running interference for the Trump administration by ignoring its apparent effort to maximize the voting power of “non-Hispanic whites.”