As argument commenced at the Supreme Court last Monday, most eyes were on Justice Antonin Scalia. While still the Court’s conservative paterfamilias, union supporters were looking to Scalia as a potential swing vote in their favor in the case, Friedrichs v. California Teachers Association. He had endorsed Abood, the precedent now under scrutiny, in a 1991 case, and strongly defended state and municipal employers’ right to limit employee speech in other contexts. However, as his questioning began, union supporters lost hope.

Scalia seemed skeptical of public-sector employers’ interests in a strong union representing workers, implying that a state would be equally well off bargaining with a weak union with fewer resources. He told the solicitor general of California that he understood “the need of the state to have an efficient system for dealing with its employees,” but questioned whether “the union would not survive without” agency fees, the payments that are at issue in the case. Later, Chief Justice Roberts echoed this view, asking for proof that “the unions are going to collapse” without agency fees. Counsel for Friedrichs put a finer point on it, arguing that “if anything, [public employers] don’t want” effective unions, “because nobody wants a strong bargaining partner that’s going to drive up public expenditures.”

In some ways, Scalia’s question was a (very) small victory for the unions. At least the conservative justice saw a state interest in allowing public workers to be represented by a union, and in ensuring the union’s minimal survival—though maybe no more than that.

Yet, Scalia’s implication missed an important fact: Many states want effective and well-resourced unions, even though those unions will be on the other side of the bargaining table. That much is apparent from California’s robust defense of its collective-bargaining law in Friedrichs, as well as the amicus briefs filed by 21 states and the District of Columbia and a list of cities, counties, elected officials, and school districts in support of California and the California Teachers Association. (I was one of the co-authors of an amicus brief on behalf of Labor Law and Labor Relations Professors in support of the state and union parties in this case.)

And there’s further proof in how many individual states have chosen to manage their employees through collective bargaining: States are not locked into a one-size-fits-all labor-relations model. If a state views unions as unhelpful partners, they are free to eliminate or curtail public-sector bargaining. Despite this, most states allow at least some public workers to bargain collectively. As a result, today about 35 percent of public-sector workers are union members. Furthermore, nearly half of states require or permit agency fees.

But what do states and other public employers gain from the existence of strong unions? During the Friedrichs argument, the solicitor general of California explained that his state’s collective-bargaining statute—which not only requires represented workers to pay agency fees, but also structures union representation in myriad other ways—was passed in response to “a long history in California in the ‘50s and 1960s of labor unrest.” California was not alone in this regard—many states first authorized public-sector bargaining in response to a wave of hugely disruptive strikes that took place in the 1960s and ‘70s. These strikes closed schools, stopped garbage pickup, ground public transit to a halt, and even left cities without the protection of firefighters and police. But implementing collective bargaining proved an effective antidote, and subsequent research has confirmed that collective bargaining curtails strikes and other disruptions in the public sector.

This result may seem counterintuitive; one might assume that eliminating public-employee unions would correspondingly eliminate public employees’ collective action. But this view misses what public unions can accomplish for their members: collecting and voicing workers’ priorities, pursuing them in bargaining, and enforcing the resulting contract. Not only do public employees value the improvements in wages and working conditions that unions win, but the opportunity to bargain itself makes workers more likely to buy into their employers’ missions and stay at their jobs. And, worker stability and voice are in turn linked to productivity gains, undermining Friedrichs’s counsel’s assumption that a strong union drives up spending. Even more important, when public unions fight for measures that help workers do their jobs safely and effectively—such as when firefighters bargain for better safety equipment or nurses bargain for lower staff-to-patient ratios—the public benefits too.

But employers are less likely to realize these benefits when a union with inadequate resources sits across the table. A union operating on a shoestring will have a difficult time being an effective conduit for the voices of the workers it represents. A union that cannot hire a qualified actuary will struggle to assess employee benefits proposals during bargaining, leaving employees without incentives to remain at their posts. A union that cannot hire lawyers to enforce a contract will quickly render its protections illusory.

The benefits of strong unions are all the more evident where innovative states and cities have prioritized collaborative labor-management relations. For example, some school districts have begun partnering with teachers’ unions to improve teacher mentoring and evaluation—one of the most fraught subjects in public employment today. Strong unions make these programs more likely to succeed by promoting teacher buy-in, channeling constructive feedback, and providing a backstop for teachers who fear that their jobs might be placed at risk if a program initially proves unsuccessful or unpopular.

Finally, agency fees allow unions to take the long view. As the U.S. solicitor general put it during argument, unions that must convince workers to choose to pay for representation that they will receive no matter what may resort to “trying to convince employees that they need the union because otherwise management is going to do them harm.” A similar concern led the state of Maryland to favor agency fees—a government report reasoned that making public unions reliant on voluntary dues might lead them to conclude they “must process every grievance, placate every member, fight for every little cause, in order to hold its membership.” But a strong union “can tell off a member just as well and sometimes better than management can.”

Will the Court see any wisdom in this argument? Based on the questions from the five more conservative justices, it seems doubtful. There’s an irony in this: The members of the Court evincing the most hostility to public-sector agency fees are also the strongest advocates for federalism, and especially for giving states a free hand in structuring their public-sector labor relations. Instead, the Court stands poised to unilaterally impose a nationwide “right to work” regime on the public sector, the culmination of decades of conservative advocacy and litigation. But if the Court strikes down agency fees, it is not just unions that will be harmed—governments and citizens who rely on public services will be as well.