WASHINGTON — The owner of an inn on the Canadian border who said he had been assaulted by a Border Patrol agent may not sue the agent for violating the Constitution by using excessive force, the Supreme Court ruled on Wednesday.

The decision, by a 6-to-3 vote along ideological lines, stopped just short of overruling a 1971 precedent, Bivens v. Six Unknown Named Agents, that allowed federal courts, rather than Congress, to authorize at least some kinds of lawsuits seeking money from federal officials accused of violating constitutional rights.

But the basic message of Wednesday’s decision, Egbert v. Boule, No. 21-147, was that only Congress can authorize such suits.

The case was brought by Robert Boule, the owner of a bed-and-breakfast in Blaine, Wash., called the Smuggler’s Inn. Mr. Boule said he had served as a confidential informant for the federal government, helping agents find and apprehend people crossing the border illegally.

In March 2014, he told Erik Egbert, a Border Patrol agent, that a Turkish citizen was scheduled to arrive at the inn.

When the guest’s car reached the inn, Mr. Egbert entered Mr. Boule’s property without a warrant. Mr. Boule said he told the agent to leave, only to be thrown against the vehicle and then to the ground.

Mr. Egbert inspected the guest’s paperwork and found it to be in order. That night, the guest unlawfully entered Canada.

Mr. Boule sued the agent, saying he had violated the Fourth Amendment by using excessive force and the First Amendment by contacting the Internal Revenue Service and prompting an audit of Mr. Boule’s tax returns.

A federal trial judge dismissed the case, saying the Bivens decision did not allow the sorts of claims Mr. Boule pressed. The U.S. Court of Appeals for the Ninth Circuit reversed that dismissal, allowing Mr. Boule to pursue both theories.

Justice Clarence Thomas, writing for five justices, said the court has only twice extended Bivens, which concerned the unconstitutional search of a home in Brooklyn, most recently in 1980. In Mr. Boule’s case, Justice Thomas wrote, “the court of appeals plainly erred when it created causes of action for Boule’s Fourth Amendment excessive-force claim and First Amendment retaliation claim.”

Justice Thomas wrote that courts should focus on a “single question” in such cases: Is there “any reason to think Congress might be better equipped” than a court to weigh the costs and benefits of allowing suits against federal officials for money?

In particular, Justice Thomas wrote, the national security interest in border security distinguished the case before the court from ordinary Fourth Amendment violations. He cited a 2020 decision rejecting a suit filed by the parents of a teenager killed by an American agent shooting across the Mexican border.

Justice Neil M. Gorsuch voted with the majority but said he would have gone further. The court, he wrote, should “forthrightly return the power to create new causes of action to the people’s representatives in Congress.”

Justice Sonia Sotomayor, joined by Justices Stephen G. Breyer and Elena Kagan, agreed that Mr. Boule could not pursue his claim under the First Amendment. But she wrote that a Fourth Amendment claim based on the agent’s use of excessive force was permitted by Bivens.

She wrote that Mr. Boule’s case “is a far cry from others in which the court declined to extend Bivens for reasons of national security or foreign relations.”

The majority’s efforts to invoke those interests, she added, were disingenuous.

“This case does not remotely implicate national security,” Justice Sotomayor wrote. “The court may wish it were otherwise, but on the facts of this case, its effort to raise the specter of national security is mere sleight of hand.”

Justice Sotomayor added that “Agent Egbert, a line officer, was engaged in a run-of-the-mill inquiry into the status of a foreign national on U.S. soil who had no actual or suggested ties to terrorism, and who recently had been through U.S. customs to boot.”

Justice Sotomayor said she held out hope that some suits under the Bivens decision might still survive.

“Although today’s opinion will make it harder for plaintiffs to bring a successful Bivens claim, even in the Fourth Amendment context,” she wrote, “the lower courts should not read it to render Bivens a dead letter.”

On the next page of her dissent, though, Justice Sotomayor seemed to concede that few if any such suits will likely succeed.

“The court’s decision today,” she wrote, “ignores our repeated recognition of the importance of Bivens actions, particularly in the Fourth Amendment search-and-seizure context, and closes the door to Bivens suits by many who will suffer serious constitutional violations at the hands of federal agents.”