In it, they wrote:
"Today, we urge you and the National Football League to send the same clear message as the NBA did: that racism and bigotry have no place in professional sports. It's time for the NFL to endorse a name change for the Washington, D.C. football team.
The despicable comments made by Mr. Sterling have opened up a national conversation about race relations. We believe this conversation is an opportunity for the NFL to take action to remove the racial slur from the name of one of its marquee franchises."
Organizations represent more than 2 million Native Americans in 300 tribes have requested a name change, saying that calling a football team the Redskins is racist.
The majority of the signers are Democrats. One Independant also joined the request. No Republicans signed letter.