The office tried to defend the disparagement clause on multiple grounds, including the argument that registering trademarks amounted to government speech—a classification that isn’t regulated by the First Amendment. The Court narrowly reached a similar conclusion two years ago in Walker v. Texas Sons of Confederate Veterans when it sided with the state’s Department of Motor Vehicles against a neo-Confederate group that sought license plates bearing Confederate insignia. But the justices rejected that argument Monday as nonsensical on its face.

“If the federal registration of a trademark makes the mark government speech, the federal government is babbling prodigiously and incoherently,” Justice Samuel Alito wrote in his opinion for the Court. “It is saying many unseemly things. It is expressing contradictory views. It is unashamedly endorsing a vast array of commercial products and services. And it is providing Delphic advice to the consuming public.”

The Court’s ruling is likely to resolve a parallel legal battle over the Washington Redskins trademark in the team’s favor. A PTO appeals board revoked six of the team’s trademarks in 2014 for violating the disparagement clause in response to a petition filed by a group of young Native American activists, who told the board that the trademarks were racial slurs. The team filed a lawsuit shortly thereafter, but a federal district court upheld the board’s decision.

With the clause struck down, the team will almost certainly win its challenge of that ruling in the Fourth Circuit Court of Appeals. Dan Snyder, the team’s owner, told the Washingtonian he was “thrilled” by the Tam ruling. He had filed a brief with the court urging it to back The Slants’ position, while a group of Native American organizations and tribes had urged the Court to view the offensive trademarks as commercial speech, a category in which courts have given state and federal governments broader deference to regulate.

The justices strongly rejected that stance, citing its potential for abuse if applied to the disparagement clause. “It is not an anti-discrimination clause; it is a happy-talk clause,” Alito quipped. In one example, he argued that with leeway so expansive, the provision could one day be used to target trademarks that disparage sexists, racists, and homophobes instead of trademarks issued by those people themselves.

“The commercial market is well stocked with merchandise that disparages prominent figures and groups, and the line between commercial and non-commercial speech is not always clear, as this case illustrates,” he explained. “If affixing the commercial label permits the suppression of any speech that may lead to political or social ‘volatility,’ free speech would be endangered.”

Anthony Kennedy echoed those themes in a concurring opinion in which he was joined by Ruth Bader Ginsburg, Sonia Sotomayor, and Elena Kagan. “A law that can be directed against speech found offensive to some portion of the public can be turned against minority and dissenting views to the detriment of all,” he wrote. “The First Amendment does not entrust that power to the government’s benevolence. Instead, our reliance must be on the substantial safeguards of free and open discussion in a democratic society.” Accordingly, the justices sided with Tam and his band.