(USA TODAY) -- Pressure on Daniel Snyder to change the name of his Washington NFL club ratcheted up significantly Thursday as a letter signed by half of the U.S. Senate was sent to NFL Commissioner Roger Goodell.
"The N.F.L. can no longer ignore this and perpetuate the use of this name as anything but what it is: a racial slur," said the letter, which was signed by 50 of the Senate's 55 Democrats.
The letter draws a parallel between the quick reaction by NBA Commissioner Adam Silver in castigating racist remarks made by Los Angeles Clippers owner Donald Sterling and the NFL insisting that the term "Redskins" is used respectfully by the team.
MORE: See the full letter and signatures (PDF)
MORE: Senator Bill Nelson's letter to NFL Commissioner Goodell (PDF)
"Today, we urge you and the National Football League to send the same clear message the NBA did: that racism and bigotry have no place in professional sports," the letter said. "It's time for the NFL to endorse a name change."
The letter was first reported in The New York Times, which said it was not circulated among Senate Republicans. The five Senate Democrats who did not sign were Mark Warner and Tim Kaine of Virginia, where the team has its practice facilities; Joe Manchin of West Virginia; Joe Donnelly of Indiana and Mark Pryor of Arkansas.
"Now is the time for the NFL to act," the letter said. "The Washington, D.C. football team is on the wrong side of history. What message does it send to punish slurs against African Americans while endorsing slurs against Native Americans?"
NFL spokesman Brian McCarthy said the NFL received the letter only after The Times got it. He sent a statement by email: "The NFL has long demonstrated a commitment to progressive leadership on issues of diversity and inclusion, both on and off the field. The intent of the team's name has always been to present a strong, positive and respectful image. The name is not used by the team or the NFL in any other context, though we respect those that view it differently."
REACTION : Will letter provoke a change?
The Washington team did not immediately respond to a request for comment. Snyder told USA TODAY Sports a year ago this month that he would never change the name.
Ten members of Congress sent Goodell a letter a year ago that also called for a name change. Goodell wrote a return letter last June in which he said the Washington team name is "a unifying force for strength, courage, pride and respect."
The U.S. Senate and U.S. Congress can exert more than pressure on the NFL, which is controversially exempt from federal income taxes as a nonprofit, as are several other pro sports leagues.
In March 2013, U.S. Delegate Eni Faleomavaega, a Democrat from American Samoa, and U.S. Rep. Tom Cole, a Republican from Oklahoma, introduced a bill that would cancel existing trademark registrations containing the term "redskins" in reference to American Indians. The bill has been referred to a subcommittee of the House Judiciary Committee.