WASHINGTON – Native American plaintiffs suing to end the trademark of the controversial Redskins National Football League team have gained new support from legal experts, social justice advocates and child psychologists.

One notable amicus brief to the plaintiffs’ September U.S. Supreme Court petition was filed in mid-October by a group of renowned researchers in the social sciences fields, including experts in the areas of stereotyping, prejudice and discrimination.

Based on scholarly evidence, the experts told the court there is “extensive and pervasive” public harm caused by the continued use of Indian mascots in professional sports.

“Social science research shows that the use of ethnic slurs like ‘redskin’ perpetuates harmful stereotypes and leads to discrimination,” the authors of the brief wrote.

Many of the researchers work at the top universities in the country.

Tribal citizens have long noted that the “redskins” term has historically been used as a derogatory reference to American Indians, in a similar way that the word “nigger” has been wrongly used toward blacks.

Historically, the word “redskins” was also used by the U.S. government as a way to refer to bounties it placed on scalped Indian heads, according to historians and legal experts.

The psychology scholars added that the affects of American Indian sports mascots are especially harmful to Native youth, tending to lower the self-esteem of Indian children and young adults.

Along those lines, they cited studies showing that exposure to Indian sports mascots depress the self-esteem and feelings of community worth and limit the aspirations of Native high school and college students.

The psychologists’ arguments weren’t the only new unique avenue of support.

A group of social justice advocacy experts also added an amicus brief in mid-October that said the Redskins trademark sets back progress and equality in American society.

“The social justice interests involved in this case go far beyond Native Americans. Either a trademark is disparaging or it is not. And if it is, it should not enjoy the perpetual protections of the United States government.”

They went on to make the case that the Redskins trademark is disparaging, and they noted, too, that numerous schools and other groups have removed offensive Native American team names in recent years.

A third amicus brief filed in October came from the National Congress of American Indians and several other Indian advocacy organizations.

The group said the Redskins’ trademark is disparaging not only to petitioners individually, but to all Native American people and should never have been registered.

All the support stems from a September legal petition filed by a group of Native Americans who asked the U.S. Supreme Court to hear their case calling for an end to the trademark of the Redskins team name and logo.

The petition requested that the high court review a lower court decision that sided against the Native Americans based on a statute of limitations-based legal concept known as laches – which the petition asserts is not applicable in this case.

It argued, too, that there is precedent for overturning the lower court’s statute of limitations-based decision, including a Third Circuit decision made by Samuel A. Alito, a current justice on the high court.

While laches makes for an interesting legal argument for lawyers and judges to ponder, it doesn’t necessarily resound on an emotional level, some legal experts have said.

The amicus briefs help fill that gap.

Richard Guest, a legal expert with the Native American Rights Fund, said the multi-pronged support briefs create more ways for the public to understand the arguments of the Indian plaintiffs.

“It becomes not just a legal argument, but a moral and psychological one, too.”

Philip Mause, a lawyer for the plaintiffs, said the briefs are persuasive.

“The psychology professors’ brief goes into an issue that we are learning more and more about: The harm to young American Indians involving mascots,” said Mause, a partner at Drinker Biddle & Reath in D.C.

“It’s new information and an important new development. It’s very helpful.”

He said all the briefs add to the debate and help strengthen the plaintiffs’ case.

Still, Mause noted, the Supreme Court chooses to hear very few cases, so it’s an “uphill battle.”

In a reply brief to the plaintiffs’ petition to the high court, the Redskins lawyers argued that laches is applicable.