The Nov. 9 order grants temporary relief to the government in a lawsuit brought by a river guide, an environmental nonprofit and an organization working to preserve a historic church in Ruidosa, Texas. The plaintiffs had challenged Homeland Security Secretary Markwayne Mullin's decision to waive environmental and conservation requirements for border construction in the region.

At issue is a federal law that gives the Homeland Security secretary broad authority to build border barriers and roads "to deter illegal crossings in areas of high illegal entry," and to waive legal requirements deemed necessary to speed construction. That law limits court challenges arising from waiver decisions to claims alleging violations of the U.S. Constitution.

The plaintiffs argued that the secretary's waivers ran afoul of the major questions doctrine, which asks whether Congress clearly authorized certain significant agency actions. On Oct. 2, the U.S. District Court for the Western District of Texas issued a preliminary injunction blocking the waivers and halting associated construction, concluding that the major questions argument qualified as a constitutional claim and was likely to succeed.

The Supreme Court disagreed. In its unsigned opinion, the court said the plaintiffs' argument challenged whether the secretary exceeded his authority under federal law, not whether he violated the Constitution.

"There is no such thing as a 'constitutional' major-questions claim," the court wrote.

The justices said the government was "exceedingly likely to prevail" on its argument that the district court lacked jurisdiction to decide that claim.

The court also weighed the government's border security interests and the financial costs of the construction halt. According to the opinion, a U.S. Customs and Border Protection official said the injunction was costing the government nearly $500,000 per day in expenses that could not be recovered.

The plaintiffs had argued that construction would diminish their ability to use and enjoy the area. The court concluded that Congress, by authorizing waivers of environmental and conservation requirements, had prioritized expedited border construction over the types of harm the plaintiffs alleged.

Justice Ketanji Brown Jackson would have denied the government's request to pause the injunction, according to the order.

The stay does not resolve the underlying lawsuit. If the government timely files a petition and the Supreme Court declines to hear the case, the stay will automatically end. If the court agrees to hear the case, the stay will remain in place until its judgment is sent to the lower court.

The Big Bend region, a remote and ecologically sensitive stretch of the Texas-Mexico border, has been a flashpoint in the broader debate over border wall construction and the use of environmental waivers to expedite it. The case now returns to the Supreme Court's shadow docket, where the justices frequently act on emergency requests without full briefing or oral argument.