The Supreme Court appeared likely Wednesday to block a group of protesters from bringing free-speech claims against two Secret Service agents who were guarding President George W. Bush during a 2004 visit to Oregon.

The court's liberal justices seemed just as reluctant as the conservatives to find that the agents violated the protesters' First Amendment rights by moving them farther away from the president while allowing a separate group of pro-Bush demonstrators to stay a bit closer.

The protesters claim they were moved for loudly expressing their opinions while Bush was having dinner at an outdoor patio and not for any genuine security reasons.

Deputy Solicitor General Ian Gershengorn argued that agents who make on-the-spot judgments about the president's security should be shielded from liability.

"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," Gershengorn told the justices.