For the most part, private companies have a lot of leeway when it comes to the reasons behind their hiring, firing and demotion decisions. The public sector, however, is different. Government employees are generally protected from employment retaliation when exercising their constitutional rights to free speech and association. But a case currently before the U.S. Supreme Court could put that protection to the test.

The civil servant at the heart of this case is a now-retired police officer named Jeffrey Heffernan. In 2006, he had recently been promoted to detective after working as a police officer for 20 years in Paterson, New Jersey. There was an upcoming mayoral election that year, and Heffernan’s mother supported the candidate running against the incumbent mayor. The yard sign showing her support had recently been stolen, so she asked her son to get her a new one.

After work one day, Heffernan went to the candidate’s campaign headquarters and picked up a new sign. Someone saw him there holding the sign and speaking to some staffers. A short time later, he got a phone call. He was being demoted, the caller said, because the (incumbent) mayor “calls the shots” and wanted him out.

Heffernan was not politically affiliated. In fact, he couldn’t even vote in that election because he didn’t live in Paterson. Nonetheless, his demotion was permanent, along with the pay cut and loss of perks that came with it. Heffernan sued the city, alleging that his First Amendment rights had been violated.

His lawsuit was originally successful, until the presiding judge decided to recuse himself. When the case was retried, it was dismissed by a judge. That decision was upheld by a federal appellate court. Both courts held that Heffernan’s free speech rights had not been violated because he hadn’t actually been campaigning for the mayor’s opponent. In short, his rights couldn’t have been violated because they were not being exercised.

That line of reasoning leads to some obvious and troubling questions. As just one example: Should it matter that he was not campaigning? The retaliation was based on the perception that he was openly supporting the mayor’s opponent, which would have been protected free speech. If a woman had been fired because her boss mistakenly thought she was pregnant, wouldn’t that nonetheless be an illegal case of pregnancy discrimination?

Thankfully, the U.S. Supreme Court agreed to hear the case. No matter how the Court rules, it could have big implications for the most fundamental rights of government employees.