In a jarring reversal of fortunes, a pending National Labor Relations Board case that was supposed to be a weapon for unionizing hundreds of thousands of low-wage fast-food workers under Obama may now morph into an anti-labor bludgeon for big business under Trump. The fate of one of the country’s largest poverty-wage workforces now hangs on an arcane legal debate over whether McDonald’s can be held responsible as a formal employer for all the workers who toil under the Golden Arches.

The McDonald’s case, dating back to 2012, aims to undo a precedent that held that fast-food mega-chains like McDonald’s aren’t technically “bosses” of workers at their chain restaurants, and instead just license franchise owners to manage their workforces and labor conditions. Holding McDonald’s responsible as a joint employer might pave the way for collective-bargaining rights, and hence unionization, under a broad contract for McDonald’s employees nationwide. (McDonald’s restaurants in other countries in fact allow unionization and, surprise, workers can earn living wages and have real power to advocate for their rights.)

The case gained momentum in 2015 when the NLRB’s general counsel advanced the joint-employer case for all the workers represented in the suit, led by SEIU and the Fight for 15 campaign. Another breakthrough came under a separate case that year, when the board ruled to broaden the joint-employer standard for workers at the recycling company Browning-Ferris Industries: That decision found that a company could be considered a joint employer, alongside a franchisee, even if it did not exert “direct control” over those employees, for workers with essentially similar duties under the same conditions. That’s right in line with the situation of typical McDonald’s workers—wearing the same uniforms everywhere, flipping the same burgers, with the same erratically scheduled, low-paid shift work—and subject to the same rampant exploitation and labor violations nationwide. That precedent was just reversed in December.

Recently, Trump-appointed General Counsel Peter Robb derailed the McDonald’s case by moving for a 60-day stay on the trial. Judge Karen Esposito initially agreed that a settlement could be finalized while the trial was paused, but on February 1, another order followed to schedule additional hearing dates from mid-March through late April.

Labor advocates have sharply opposed a premature settlement, arguing that due process required “allowing all parties to make a fully informed, rational judgment about the relative strengths and weaknesses, legal and evidentiary, of all competing positions in this case.” Following Robb’s request to stay the trial, the Fight for 15 representatives argued that there was, after hundreds of hours of testimony over about 150 days, “no justification for disadvantaging one side in potential settlement discussions” by suspending the final phase of the trial.

Though the decision would likely go against the workers, letting the trial run its course could have more global long-term benefits. As a matter of due process, a complete trial would at least provide a public record of each side’s argument, enabling their claims to be heard in a relatively objective arena. Moreover, even following a ruling in favor of McDonald’s, a strong dissent from the minority could shed light on the board’s legal assessment and inform future debates on the scope of labor law for franchise workers and subcontracted labor forces, especially the many low-wage workers excluded from collective-bargaining rights by complex contracting arrangements.

According to Sharon Block, s former NLRB member under Obama and now director of Harvard’s Labor and Worklife Program, a full and fair trial would, if nothing else, expose the sham of Trump’s “populist” image, and help dispel any myths surrounding the White House’s sympathies with working-class voters. “If the facts are as strong as they seem to be but the board still fails to find joint employer status, it will be clear to the public what really happened—the Trump administration putting a finger on the scales for corporate America and not working Americans.”

Michael Oswalt, professor at Northern Illinois University Law School and a former member of the trial team in the McDonald’s suit, says that while the board itself may be stacked against the workers, the political balance of power is at a historical tipping point. If the parties hold off on a settlement and simply let the trial run its course, rather than settle before the final round of hearings, Oswalt speculates, “I think the immediate press, employee, and Fight for 15 spotlight on McDonald’s labor practices—founded on the narrow standard employers say they want and that conservatives think is fair—would be incredibly bright.”

The case is also unfolding in a context of turmoil throughout the NLRB. Other decisions under the Trump administration have signaled dramatic reversals of the Obama-era policies, including not only pro-business rulings but wholesale dismantling of the entire board structure under the guise of “restructuring.” (Reports have emerged of internal rifts and ideological tensions as agency leaders move to consolidate decision-making power and sideline career staffers, known for their pro-labor bent.)

Amid this war of attrition, any public scrutiny, even in the wake of a negative decision, would, in Oswalt’s view, “put McDonald’s and the management community on the defensive at a time when they are prepared for a slew of labor board reversals and victories.” Beyond this administration, “McDonald’s is effectively a test case, and even if the decision did not hold up in Washington, DC, it could create momentum for more cases in the future.”

With a pro-corporate NLRB, reversing the Trump train is near impossible—but with the Fight for 15 riding one key impending trial, pushing through one more challenge to an outdated law could spark some vital friction in the streets.