The Supreme Court hears a labor dispute on Tuesday involving striking truck drivers who walked off the job to try to secure a better contract from their employer, a company that provides premixed concrete for construction projects. Yet, while Glacier Northwest v. International Brotherhood of Teamsters is a fairly unremarkable case, the stakes for unionized workers could be enormous.

Glacier Northwest, the employer beyond this case, seeks to upend a more than 60-year-old rule protecting unions from lawsuits when workers exercise their federally protected right to strike.

It’s an audacious ask, and the case could potentially be decided more narrowly. But the two-thirds of the Court that was appointed by Republicans has shown extraordinary hostility toward unions in the past. So we can’t dismiss the risk that the Court hands down a maximalist decision that upends the balance of power between employers and labor unions.

The case hinges on a rule protecting workers’ right to strike, and laying out how companies can claim that this rule does not apply to a particular strike.