Correction: An earlier version of this article incorrectly described where the protest against President George W. Bush occurred. It took place in Jacksonville, Ore., not Jacksonville, Fla. This version has been corrected.

The exterior of the U.S. Supreme Court is seen in Washington March 5. (Gary Cameron/Reuters)

A Supreme Court hearing that aired all sorts of ways someone might try to assassinate the president did not bode well Wednesday for a group of protesters suing two Secret Service agents for allegedly mistreating them at a 2004 appearance of President George W. Bush.

Several justices seemed concerned about whether the free speech rights of anti-Bush protesters in Jacksonville, Ore., had been violated. They were kept farther away from the president than another group that supported him, and there is no allegation that the demonstrators meant the president any harm.

But the court gave no indication that it would let a lawsuit proceed against the two agents in charge if there were any possibility that they had been making on-the-spot decisions about the president’s safety.

Agents generally are shielded from damages arising from their official actions, and the question after the hearing seemed to be whether the court would make it even harder to bring suits.

Justice Antonin Scalia scolded Deputy Solicitor General Ian H. Gershengorn, representing the government and the agents, for not wanting to “win big” when Gershengorn suggested that it might be possible in other cases to bring a suit alleging viewpoint discrimination.

All that should be asked, Scalia said, is “was there objectively a reason to move these people? If there was, [even] if you had an ulterior motive that was unconstitutional, we don’t inquire into it.”

Other justices weren’t ready to go that far. But each one who spoke showed concern about second-guessing Secret Service agents. Justice Elena Kagan said demonstrators were close enough to the six-foot fence around the patio to “throw a grenade.”

Chief Justice John G. Roberts Jr. asked the protesters’ lawyer, Steven M. Wilker of Portland, Ore., to imagine that he was head of the security detail and had to immediately remove the president through one of two groups of demonstrators.

“Do you go through the anti-Bush crowd or through the pro-Bush crowd? You’ve got to decide right now, quickly. I’m serious. You have to make a split-second decision,” Roberts ordered.

When Wilker paused and began to equivocate, Roberts said: “It’s too late. You’ve taken too long to decide.”

Wilker said it was hard for him to answer the question because he is “not a security expert.”

Said Scalia, “You’re the farthest thing from a security expert if you don’t know the answer to that one.”

Wilker said that Roberts’s hypothetical scenario was not representative of the case at hand.

When Bush made his impromptu decision to dine al fresco, two groups were assembled nearby. Between 200 and 300 people unhappy with the president gathered in their assigned spot on the street and sidewalks immediately adjacent, while a group of Bush supporters collected a block away.

About 15 minutes after the president was seated and a noisy protest began, the anti-Bush crowd was moved farther away, while the supporters were left where they were. When the motorcade departed, Bush drove past the supporters, but the protesters were not on the route.

Seven protesters sued Secret Service agents Tim Wood and Rob Savage, saying the unequal treatment violated free speech rights. Represented by the American Civil Liberties Union, the protesters allege that it was one of more than a dozen instances in which demonstrators were treated differently based on whether they supported or opposed Bush.

Wilker noted that a “presidential advance manual” advised White House staff members to work with agents to set up protest areas that were “preferably not in view of the event site or motorcade route.”

Some justices expressed concern about the disparate treatment. Kagan asked if the Secret Service could make demonstrators move simply because they were “annoying” the president. Justice Sonia Sotomayor asked Gershengorn why the Bush protesters weren’t moved, because they were also within “throwing distance of a bomb or shooting distance as well.”

He replied that a two-story building separated them from the patio.

Justice Anthony M. Kennedy asked if the government’s position was that even though protesters’ have a First Amendment right to speech, it was “virtually unenforceable” in matters of crowd control.

“Because it seems to me if this complaint doesn’t survive, nothing will,” he said.

Gershengorn replied that some suits might be worthy, but not those that target individual agents for personal damages.

As the court has noted in other cases, Gershengorn said, “there are times when we don’t want a reasonable official to hesitate before he acts and nowhere is that more important than when the specter of presidential assassination is in order.”

The case is Wood v. Moss.