The face of the case that could cripple public sector unions, argued earlier this week at the Supreme Court, is a blonde, curly-haired elementary school teacher from Orange County.

Rebecca Friedrichs told (and retold) a story of battling teachers unions for the best interests of her students as the suit has blazed through the legal system, serving as an example for conservative-backed educational reformers who see those unions as the enemies of progress.

“We really couldn’t have asked for a better spokesman than Rebecca,” said lead litigator Michael Carvin, a co-founder of the Center for Individual Rights, which had been looking for a test case to challenge the union practice of charging “agency fees” to non-members for the cost of administering the contract.

But elementary school teachers are far from the only public servants the case will impact.

If Friedrichs and her backers win — as seems possible, if the justices’ critical questioning from the bench is any indication — the verdict will also instantly apply to police and firefighters. Many of them had escaped Republican attacks that have hobbled labor in states like Wisconsin and Michigan, where public safety unions have been less solidly aligned with the Democratic party than have other government workers.

And that’s why the Friedrichs case could have a bearing on another debate that’s been unfolding across America in recent years: The role of police unions in protecting officers who may have violated the law in the course of carrying out their duties. Black Lives Matter protesters and civil rights organizations have zeroed in on provisions of police contracts that shield them from accountability.

“Many protections given to officers who find themselves accused of wrongdoing contribute to the blue wall of silence that has so denigrated the image of police in the public’s eyes,” says Janai Nelson, associate director of the NAACP Legal Defense Fund, which is developing a strategy to challenge what it sees as the most egregious contract provisions.  “They’re not, and should not be used as a tool to protect civil servants from the fair enforcement of laws.”

Nelson is careful to say that she doesn’t oppose the rights of police to form unions, as some activists have done. But the explosion of attention to police violence has put the labor movement in the awkward position of standing for racial justice while not breaking solidarity.

“We respect the work that our police officers do, but when a black male is 21 times more likely to be killed by police, we see it as a systemic problem,” says United Steelworkers vice president Fred Redmond, who serves on a commission on race and labor formed last year by the AFL-CIO. “Issues that affect the black community should be at the forefront of labor.”

But when asked at a forum this week how discussions between police and advocates for racial equity had been going, AFL-CIO president Richard Trumka responded cautiously. “The police look at it and say, ‘My life is on the line every day,’” he said. “It’s a slow, fragile process, slower than I had hoped for and imagined.”

So how might the Friedrichs case affect the strength of police unions, and the attitude they take in flare-ups around allegations of misconduct? The evidence is mixed.

On the one hand, freeing union members of their obligation to pay dues may fracture the organizations. “In all of the recent controversies, the union is the public face of the rank and file,” says Sam Walker, an emeritus professor of criminal justice at the University of Nebraska at Omaha. "I think in many, probably most police departments, it is not truly representative.”

That’s in part because, despite the increasing diversity of police forces themselves, the unions haven’t always kept pace. “In lots of departments, the union is dominated by white males,” Walker says. "African American and Hispanic officers haven’t felt supported by the union, so they may leave. The same is true for female officers. This could increase the more open splintering of the rank-and-file workforce.”

An exodus of members would shrink the funding available for police unions to back political candidates who support their interests, such as funding for equipment and personnel. It also might make it more difficult for them to maintain contract provisions that have made it difficult to prosecute police officers accused of using excessive force.

On the other hand, it's possible that police unions might not suffer much at all relative to their public sector brothers and sisters.

Police unions do more than just negotiate collective bargaining agreements, says Max Schanzenbach, a professor at the Northwestern University School of Law who is examining the Chicago police contract. They also cover the cost of legal representation if an officer is accused of misconduct, serving as a kind of malpractice insurance. While unions are required to serve even non-members in the grievance process, that obligation doesn’t extend to arbitration proceedings, where an officer can be disciplined.

"The police do have an incentive to join the union so that the union provides services for them,” Schanzenbach says. "The free rider problem that everybody's talking about could be overcome if you said that 'if you don’t pay your dues, we won’t pay for your arbitration.'”

That’s a better value proposition than what other unions usually offer. "Teachers, on the other hand, see the value as more contract negotiation related,” says Dennis Kenney, a professor at the John Jay College of Criminal Justice. “That hasn’t gone so well of late and besides, an individual still benefits from a contract even if not in the union. Not having to pay dues but still getting the benefit will more likely appeal.”

Chuck Canterbury, national president of the Fraternal Order of Police, agrees. While blasting the arguments of plaintiffs in the Friedrichs case — which the police groups' amicus briefs fleshed out in full — Canterbury thinks that police unions might actually make out okay.

“Our line of legal defense is usually more costly — there’s more chances where you could be accused of a crime,” Canterbury says. “I believe that’s what gives law enforcement associations and unions more traction with their members.”

Plus, he says, unions have become even more important at a time when increased public scrutiny has led to mandates that officers aren’t used to — like wearing body cameras — that have changed the rules of engagement.

“The department’s telling us we’ve got to do this, but we’ve got no training,” Canterbury says he’s heard from rank-and-file officers. "If I don’t know what’s legal and what’s not legal, what’s a police officer supposed to do?”

Max Ehrenfreund contributed to this report.