WASHINGTON, DC-A landmark decision from the U.S. Supreme Court threatens the long-running case against the Washington NFL team's racist mascot.

A group of young Native activists, led by Navajo Nation citizen Amanda Blackhorse, had secured victory when the U.S. Patent and Trademark Office said the team's symbols were "disparaging" to Native peoples. A federal judge agreed.

But on June 19, 2017, the nation's highest court, in a complex ruling, changed the game. By a majority vote, the justices held that the federal law utilized by Blackhorse and her allies is unconstitutional.

The ruling came in Matal v. Tam, a closely-related trademark case. Blackhorse and her fellow Native activists, along with several tribes and inter-tribal organizations, submitted briefs to the Supreme Court in hopes of protecting the Lanham Act, the federal law at issue.

Justice Samuel Alito rejected those calls in an opinion that was joined by all of his colleagues. He cited the tribal brief no less than three times in explaining why the law violates the right to free speech promised by the First Amendment to the U.S. Constitution.

"Speech that demeans on the basis of race, ethnicity, gender, religion, age, disability, or any other similar ground is hateful; but the proudest boast of our free speech jurisprudence is that we protect the freedom to express 'the thought that we hate,'" Alito wrote for the court in the 25-page opinion.

The Supreme Court took action almost three years to the day of the Native activists' original victory against the NFL team. In Blackhorse v. Pro Football, Inc., the Trademark Trial and Appeal Board said six "Redskins" marks could not be registered under the Lanham Act because they disparaged Native peoples and brought them into disrepute.

The team immediately fought the ruling by taking it to the federal court system. A year later, in July 2015, Judge Gerald Bruce Lee upheld the board in another victory for the activists.

"The record contains several dictionaries defining 'redskins' as a term referring to North American Indians and characterizing 'redskins' as offensive or contemptuous," wrote Lee, who is based in Virginia, where the Washington team maintains a headquarters and training facilities.

The battle took a more longwinded turn as the team asked the 4th Circuit Court of Appeals, also based in Virginia, to overturn the ruling. But before arguments were even heard, Pro-Football tried to get its case to the Supreme Court by capitalizing on Tam, which had already been added to the docket.

Although the Supreme Court turned away the request, the team sought to delay proceedings in the 4th Circuit. The case was put on hold in order to wait for the outcome in Tam, which was one of the closely-watched petitions of the current term.

Justice Samuel Alito, who wrote the opinion, said of the provision:

"It offends a bedrock First Amendment principle. Speech may not be banned on the grounds that it expresses ideas that offend."