WASHINGTON — The Supreme Court ruled Monday that a law that prohibits the government from registering trademarks that “disparage” others violates the First Amendment, a decision that could impact the Washington Redskins’ efforts to hang on to its controversial name.

Justice Samuel Alito delivered the opinion for a largely united court. He said the law could not be saved just because it evenhandedly prohibits disparagement of all groups.

“In the sense relevant here, that is viewpoint discrimination,” Alito wrote. “Giving offense is a viewpoint.”

The trademark office in 2011 said registering the trademark of the Slants, an Asian American rock group, would violate a part of the 1946 Lanham Trademark Act that prohibits registration of a trademark that “may disparage . . . persons, living or dead, institutions, beliefs, or national symbols, or bring them into contempt, or disrepute.”

The office said the name was likely to disparage a significant number of Asian-Americans. But founder Simon Tam said the point of the band’s name is just the opposite: an attempt to reclaim a slur and use it “as a badge of pride.”

Tam lost in the first legal rounds. But then a majority of the U.S. Court of Appeals for the Federal Circuit said the law violates the First Amendment’s guarantee of free speech. The government may not “penalize private speech merely because it disapproves of the message it conveys,” a majority of the court found.

The outcome is likely to affect the legal case of the Washington Redskins, whose trademark registration was revoked in 2014 under the same disparagement clause.

The Redskins filed an amicus brief supporting the Slants.

The team’s trademark registration was canceled in 2014 after decades of use. The team asked a district judge in Virginia to overturn the cancellation and was refused. The case is now in the U.S. Court of Appeals for the 4th Circuit in Richmond, pending the Supreme Court’s decision in the Slants case.

Registration of a trademark provides a nationwide defense against others who would try to use it.

The case is Matal v. Tam.

In this Sept. 18, 2016, photo, a Washington Redskins helmet is seen on the sidelines during the first half of an NFL football game against the Dallas Cowboys in Landover, Maryland. The Supreme Court on Monday, June 19, 2017, struck down part of a law that bans offensive trademarks in a ruling that is expected to help the Washington Redskins in their legal fight over the team name. (AP Photo/Nick Wass, File)
AP