John Dennis Apel in the front yard of the Catholic Workers home he runs with his wife in Guadalupe, Calif., before heading to his monthly protest outside the nearby Vandenberg Air Force Base. (Jamie Rector/For The Washington Post)

John Dennis Apel, an antiwar protester arrested on a California military base for demonstrating in a spot set aside for public protests, thought he had a pretty good free-speech case for the Supreme Court on Wednesday.

Most of the justices think otherwise — at least for now.

Members of the court repeatedly shut down Apel attorney Erwin Chemerinsky when he tried to raise Apel’s constitutional rights as part of the court’s consideration of a federal law that allows commanders to bar a person from a military base.

“You keep sliding into the First Amendment issue, which is not the issue” on which the court accepted the case, Justice Antonin Scalia said. “We’re only interested in whether the statute applies.”

Chemerinsky said the statute must be considered in tandem with Apel’s free-speech rights.

“You can raise it, but we don’t have to listen to it,” Scalia replied.

Apel, 63, is a longtime peace activist who has protested at Vandenberg Air Force Base for more than a decade. But he was barred from the base after throwing blood on the Vandenberg entrance sign in a protest in advance of the Iraq war.

He and like-minded activists have continued to protest on the first Wednesday of every month at a site along the Pacific Coast Highway, which runs through the base, that has been set aside for protesters since 1989.

But Apel was arrested several times in 2010 and received misdemeanor convictions for violating a federal law that forbids a person from entering a military base after being ordered not to do so by the commanding officer.

The U.S. Court of Appeals for the 9th Circuit in San Francisco overturned the convictions. It said that commanders have such authority only on property exclusively controlled by the U.S. government and that the base shared control of the highway with the state of California and the county of Santa Barbara.

The court did not address Apel’s First Amendment arguments.

Assistant Solicitor General Benjamin J. Horwich, representing the government, said the appeals court decision imposed an “exclusive possession” requirement that “isn’t anywhere in the text of the statute.”

Most justices seemed to agree with Horwich, saying that the base commander does not cede control over who may be on the base just because civilians are allowed to travel on major highways in the 22-square-mile base. (Apel, too, is allowed to travel the roads, as long as he does not stop and get out.)

But Justice Sonia Sotomayor pointed out that there is a difference between all the land the base owns and what it uses for military purposes. The protest zone, for instance, abuts a public middle school on base property.

“I’m not quite sure how you can keep a person off of lands that the military is not using in its operations,” Sotomayor said.

The base has painted a green line on the highway that Chemerinsky said was to delineate the “military installation” part of the base from surrounding government-owned lands. Apel was arrested on the opposite side of the green line from the guarded gates at the main entrance.

But Horwich said the base maintains the right to close all roads when the commander deems it necessary for military activities. And the rural stretches of Vandenberg “are there precisely to serve as a kind of buffer zone around these enormous rocket launches.”

The federal law refers to a military “reservation, post, fort, arsenal, yard, station or installation.” Chemerinksy said that means not all the base is covered.

“The United States can draw the green line and build the fence wherever it chooses,” said Chemerinksy, who is dean of the law school at the University of California at Irvine. “Here, it decided to do so in a particular place, leaving open a fully open public road with a designated protest zone.” That is a sign national security is not implicated, he said.

But Chief Justice John G. Roberts Jr. said that is “usually the sort of determination that’s left to the military commander. I can think of a lot of reasons why the commander would not want a gathering of people on the road but would be willing to let people drive through the road.”

Roberts said the commander also had good reason to ban Apel because of his vandalism in 2002.

But Chemerinksy said the Supreme Court “has never said there’s a permanent forfeiture of First Amendment rights because somebody misbehaved at one time.”

Despite their reluctance to engage on the free-speech issue, some justices indicated there might be a First Amendment argument for Apel. As Chemerinsky pointed out, the court has decided in the past that a public road on a military base was a fitting place for public protest.

The government said the proper course in Apel’s case would be to reverse the 9th Circuit’s ruling on the federal statute and remand the case to the lower court for consideration of the protester’s free-speech rights.

The case is U.S. v. Apel .