The Supreme Court sided with the Postal Service on Tuesday over its claims of immunity in a lawsuit filed by a landlord who claimed the USPS racially discriminated against her by intentionally not delivering her mail.

The justices ruled 5-4 in favor of the Postal Service, with Justice Clarence Thomas penning the majority opinion, which Chief Justice John Roberts, along with Justices Samuel Alito, Brett Kavanaugh, and Amy Coney Barrett, joined.

“Congress retained sovereign immunity for a wide range of claims about mail,” Thomas wrote for the majority. “Specifically, the [Federal Tort Claims Act’s] postal exception retains sovereign immunity for all claims ‘arising out of the loss, miscarriage, or negligent transmission of letters or postal matter.'”

“This case concerns whether this exception applies when postal workers intentionally fail to deliver the mail,” Thomas added. “We hold that it does.”

Lebene Konan filed the lawsuit against the USPS after she claimed that it intentionally did not deliver mail to two of her properties as part of a “campaign of racial harassment.” The USPS argued it was immune from the lawsuit under federal law, but also that the mail was not delivered for technical reasons, not racial ones. The immunity question was the only one before the justices at this stage of the case.

Thomas wrote in his opinion that even in cases in which the USPS intentionally fails to deliver mail to an address, it is immune from a lawsuit.

“Given the frequency of postal workers’ interactions with citizens, those suits would arise so often that they would create a significant burden for the Government and the courts,” Thomas wrote.

“And their cost to taxpayers would depend on the value and importance of the mail’s contents, over which the Government typically has no control,” he added.

The majority ruling reverses the finding of the U.S. Court of Appeals for the 5th Circuit, which had held the USPS was not immune to the lawsuit over intentionally undelivered mail.

Justice Sonia Sotomayor wrote the dissent, which was joined by Justices Elena Kagan, Neil Gorsuch, and Ketanji Brown Jackson. Sotomayor argued the high court’s majority opinion expands the scope of exceptions given to the USPS under the Federal Tort Claims Act.

“Today, the Court holds that one exception—the postal exception—prevents individuals from recovering for injuries based on a postal employee’s intentional misconduct, including when an employee maliciously withholds their mail,” Sotomayor wrote. “Because this reading of the postal exception transforms, rather than honors, the exception Congress enacted, I respectfully dissent.”

Sotomayor also argued that even if ruling in favor of Konan opened the door to more lawsuits against the Postal Service, “that would not provide this Court with authority to change the text Congress enacted.”

“Ultimately, this regime is the consequence of Congress’s choice to have the exception turn on certain types of misconduct, rather than providing the Postal Service with a blanket exception,” Sotomayor wrote. “It is not the role of the Judiciary to supplant the choice Congress made because it would have chosen differently.”

The Supreme Court is expected to announce at least one ruling on Wednesday, as the justices continue with arguments and rulings for their current term, which is expected to end at the end of June when final rulings are released.