WASHINGTON (Reuters) - The U.S. Supreme Court ruled on Tuesday that a former police detective can sue a New Jersey city claiming he was demoted as punishment after getting a campaign sign for his bedridden mother supporting the mayor’s rival in a 2006 local election. The court, in its 6-2 ruling, found that Jeffrey Heffernan, a now former member of Paterson’s police force, was not in fact exercising his rights to freedom of association under the U.S. Constitution’s First Amendment because he picked up the sign for his mother and not himself. But the justices decided he could sue the city for violating those rights because the boss who demoted him believed, albeit mistakenly, that Heffernan supported the mayor’s opponent. “We conclude that ... the government’s reason for demoting Heffernan is what counts here,” Justice Stephen Breyer wrote for the court. “When an employer demotes an employee out of a desire to prevent the employee from engaging in political activity that the First Amendment protects, the employee is entitled to challenge that unlawful action ... even if, as here, the employer makes a factual mistake about the employee’s behavior.” The high court reversed a 2015 ruling by the Philadelphia-based 3rd U.S. Circuit Court of Appeals dismissing Heffernan’s lawsuit on the grounds that a First Amendment retaliation claim cannot be based on an employer’s perception of a worker’s actions. The day before Heffernan was demoted, an aide to Jose Torres, Paterson’s mayor at the time who was running for re-election, saw Heffernan getting a large campaign sign backing another mayoral candidate. Heffernan said he got the sign while off-duty as a favor for his mother after her previous sign had been stolen from her front yard, and that the sign did not reflect his personal preference in the mayoral election. The next day, the police department demoted him from detective and transferred him to the traffic division’s walking squad, a move he saw as political retaliation. Justice Clarence Thomas wrote the dissenting opinion, arguing that Heffernan should not be able to sue regardless of whether his demotion was misguided or wrong because he had not been exercising his constitutional rights.    
U.S. top court backs New Jersey cop's political retaliation claim