If we had a fair Supreme Court not driven by partisanship in its most political cases, Thursday’s blockbuster revelation in the census case would lead the court to unanimously rule in Department of Commerce v. New York to exclude the controversial citizenship question from the decennial survey. Those newly revealed documents show that the Trump administration’s purpose in putting the citizenship question on the upcoming census was not its stated one to help Hispanic voters under the Voting Rights Act, but rather to create policy that would be “a disadvantage to the Democrats” and “advantageous to Republicans and non-Hispanic Whites.” It’s difficult to produce a greater smoking gun than explicitly saying you are hoping to help the GOP by increasing white voting power. But this revelation, coming from the hard drive of a deceased Republican political operative and made available to Common Cause by his estranged daughter, is ironically more likely to lead the Republican-appointed conservative justices on the Supreme Court to allow the administration to include the question that would help states dilute the power of Hispanic voters.

As I explained in Slate back in March, the U.S. government is defending the inclusion of a question about citizenship for the first time since the 1950 census as needed to provide accurate demographic information to the Department of Justice to help it protect Latinos in Voting Rights Act lawsuits. Two lower courts had found that Commerce Secretary Wilbur Ross insisted on including the citizenship question for undisclosed reasons and that the DOJ voting rights claim was a mere pretext. Republicans have again lined up in favor of including the question, which Democrats oppose as likely to inhibit a complete and accurate count of all persons in the United States as explicitly demanded by the Constitution, leading to lower representation in Democratic-leaning areas and fewer federal resources based on population.

The case should be an easy one for the Supreme Court. The Commerce Department’s decision to include the citizenship question is a textbook example of arbitrary and capricious action in violation of the Administrative Procedure Act. The only justification that the department has offered for including the question—aiding in DOJ efforts to help Latinos in voting rights cases—had already been shown to be a pretext.

But at the Supreme Court oral argument, as Mark Joseph Stern reported for Slate, the conservative justices on the court offered disingenuous arguments in favor of the government. Those justices, who are usually hostile to the Voting Rights Act, took at face value the government’s assertion that the question was necessary to protect Hispanic voters, despite uncontradicted evidence that voting rights advocates don’t need the census data to defend their cases and despite the Trump administration not bringing a single Voting Rights Act Section 2 case defending Hispanic voters. They pointed to foreign practices despite an aversion to citing other countries’ cases in opinions. Most disingenuously, some of the conservative justices rejected the uncontradicted scientific evidence—some offered by those working for the Census Bureau itself—that adding the question will depress turnout, especially among Hispanics.

These justices signaled that they were willing to defer to agency decision-making even when they have questioned such deference in other contexts. Never mind Ross’ real reason for including the citizenship question if Congress gives him broad discretion over how to craft the questionnaire.

And here is where Thursday’s revelations fit in. The New York Times reported that the hard drive of the late Republican redistricting guru Thomas B. Hofeller contained documents indicating that the real purpose of including the citizenship question was to allow Republicans to draw new congressional, state, and local legislative districts using equal numbers of eligible voters in each district, not equal numbers of persons, a standard that would greatly reduce the power of Hispanics and Democrats in places like Texas. According to the Times, files on Hofeller’s hard drives, subpoenaed in litigation concerning North Carolina redistricting, show that Hofeller “wrote a study in 2015 concluding that adding a citizenship question to the census would allow Republicans to draft even more extreme gerrymandered maps to stymie Democrats. And months after urging President Trump’s transition team to tack the question onto the census, he wrote the key portion of a draft Justice Department letter claiming the question was needed to enforce the 1965 Voting Rights Act—the rationale the administration later used to justify its decision.”

Indeed, the new documents should make that case indisputable. Hofeller’s documents describe how obtaining citizenship data would allow those drawing district lines to specifically harm Hispanic voters by packing even more of them into “Latino districts to bring their populations up to acceptable levels.” Common Cause also discovered a direct paper trail from the Hofeller documents to the pretextual DOJ request for the census question. The DOJ version of the Voting Rights Act enforcement request cited a paragraph from Hofeller’s work verbatim and included much of the exact same substance of Hofeller’s research presented in the exact same order. In the court proceedings, though, administration officials actively hid Hofeller’s involvement. Again, all of this should be a slam dunk. For the court’s conservatives, though, it likely won’t be.

The case should be an easy one for the Supreme Court.

The question whether it is permissible to draw districts in the way Hofeller wanted is an open one. Ed Blum brought a 2016 case, Evenwel v. Abbott, in which the court unanimously rejected Blum’s argument that the state of Texas was constitutionally required to draw districts with equal numbers of eligible voters. But the majority opinion by Justice Ruth Bader Ginsburg did not go further and reach the question whether drawing districts in this way—which would exclude not just noncitizens but also children and felons from the count—violates the Constitution’s equal protection clause. “Because history, precedent, and practice suffice to reveal the infirmity of appellants’ claims, we need not and do not resolve whether, as Texas now argues, States may draw districts to equalize voter-eligible population rather than total population,” Ginsburg concluded.

Justices Clarence Thomas and Samuel Alito, however, wrote concurrences affirming their belief that states have the right to draw districts in this way. There is good reason to believe that the other conservative justices would come along should they have to decide the issue. The newly revealed census documents may now give them the opportunity to do just that.

All of that means that the Supreme Court will likely go along with Ross’ true purpose in including the citizenship question on the census: to allow states to draw districts with equal numbers of voter-eligible persons rather than total persons. The smoking-gun evidence showing that government officials lied in offering the Voting Rights Act excuse for including the question likely will be seen by these justices as irrelevant if the real reason is a permissible one.

This is not how the census case should be decided. The government should have to offer its real reasons for taking government actions and defend its actions on those terms. And even if it is otherwise constitutionally permissible to experiment with different understandings of how to draw districts with equal populations under the equal protection clause, the government should not be able to do so if the purpose is to dilute the power of political adversaries and minority voters, as demonstrated in this case by the new revelations.

Thursday’s revelations should be damning. The ACLU is already seeking sanctions in the trial court in the census case for government officials lying about the real reason for including the citizenship question. But instead the revelations may help to prop up a case that should embarrass government lawyers to argue.