GOP Senators Slam Donald Trump for Racially Charged Tweets About Wounded Knee Massacre Mocking Elizabeth Warren

Senators from within President Donald Trump's own party have spoken out against tweets he posted in the early hours of Monday morning mocking Massachusetts Senator Elizabeth Warren, which critics called racist.

Two Republican senators from South Dakota—Mike Rounds and John Thune—took issue with Trump's use of racially charged language to mock Warren. The president's tweet was in reference to a video shot in Warren's home on New Year's Eve in which she officially announced that she would be a presidential candidate for the 2020 election.

Read more: Donald Trump goes on late-night racially charged rant about Elizabeth Warren, calls her "Pocahontas" again

Trump and his supporters have regularly attacked Warren for her claim—proved accurate in October—that she has Native American heritage. As with many of his opponents, Trump has assigned his 2020 challenger a derogatory nickname—Pocahontas.

"If Elizabeth Warren, often referred to by me as Pocahontas, did this commercial from Bighorn or Wounded Knee instead of her kitchen, with her husband dressed in full Indian garb, it would have been a smash!" the president tweeted Monday.

He immediately drew criticism for his off-hand reference to the Wounded Knee Massacre, where hundreds of Native American men, women and children were slaughtered by U.S. forces in South Dakota in 1890.

Rounds posted his own tweets, seeking to remind the president of the violent and tragic nature of the Wounded Knee massacre, which he called "one of the darkest moments in our history." He noted that some 80,000 tribal members still lived close the area, and warned that the event "should never be used as a punchline."

Rounds also invited Trump to visit said tribal communities in South Dakota, telling the divisive president, "We must strive to always work together, improve relationships, celebrate our diversity and mend our history through reconciliation & mutual respect."

Thune, who has previously criticized Trump's conduct, told reporters: "That's obviously a very sensitive part of our state's history," The Hill reported. "I wish he wouldn't tweet as much, [as] I've said many times in the past," he added. "So yeah, I wish he'd stay away from it."

One hundred years after the massacre in 1990, the U.S. Congress passed a resolution expressing its "deep regret" for the incident, which is considered to have marked the end of a long period of conflict between settlers and natives. The measure did not include any reparations.

In her announcement video that so riled the president, Warren drank a beer and introduced her husband Bruce, telling him, "I'm glad you're here." Trump also responded to this part of the footage: "It's their house, he's supposed to be there!"

The president branded the video a "catastrophe," though it is not clear why he waited two weeks to launch his attack.

Donald Trump Elizabeth Warren Native American
President Donald Trump answers questions from the press as he leaves the White House on January 14 in Washington, D.C. Win McNamee/Getty Images