WASHINGTON—Several Supreme Court justices Tuesday questioned the basis of a New Jersey police officer’s claim that his demotion was based on a perception of political association, and therefore unconstitutional, because the officer acknowledges he was never actually exercising his right to free speech or association.

Jeffery Heffernan, who was a police officer in Paterson, New Jersey, went while off-duty to the office of the candidate running against the incumbent mayor to pick up a lawn sign for his mother, who supported the opponent. Word erroneously spread around the police department that Heffernan supported the candidate, and he was demoted.

During arguments before the high court, Mark B. Frost, Heffernan’s attorney, came under pressure almost immediately from Justice Anthony Kennedy and Justice Antonin Scalia, who each pressed Frost on how Heffernan could have a First Amendment claim if he was not actually exercising his right to free speech or association.

Several of the justices, including Scalia, seemed incredulous that Heffernan was pursuing the case as a constitutional issue.

“There’s no constitutional right not to be fired for the wrong reason,” he said. “And that’s what happened here.”

If Heffernan had been actively campaigning for a candidate, his behavior would have been protected by the First Amendment’s guarantee of free political association, and the city would have been violating the Constitution if it took action against him because of it. However, Heffernan was not supporting the candidate and was therefore not engaged in political association. Heffernan claims that the city violated his First Amendment rights by punishing him for what it saw as political association, even though he had no such association.

Both Frost and Assistant Solicitor General Ginger Anders claimed that ruling against Heffernan would have a “chilling effect” on the ability of public employees to take unpopular political positions.

“Other employees will know the employer expects political orthodoxy,” Anders said.

Justice Elena Kagan seemed to agree with that argument when she questioned Thomas Goldstein, the attorney for the Paterson, and said that if the First Amendment was designed to allow people to freely speak or associate in ways that are contrary to the government, then it would seem crucial to take into account the government’s motive in taking action involving someone perceived to be engaging in political speech.

Goldstein made his own “chilling” argument. He said that if the court ruled on behalf of Heffernan, then any public employee could use the argument to challenge any action by an employer. An employee who has taken no political action could allege the employer thought he had – an allegation that is hard to disprove, Goldstein said.

Kennedy, who is often the high court’s swing vote, questioned both sides. A decision is expected by summer.