Senate Republicans late Tuesday voted to block Sen. Elizabeth Warren, D-Mass., from engaging in any more debate over President Trump's attorney general nomination, after deciding that Warren impugned the motives and conduct of the nominee, Sen. Jeff Sessions, R-Ala.

The rare move came after Warren sparked a floor fight by reading harsh critiques of Sessions from 30 years ago, when he was trying to secure confirmation as a federal judge.

Sessions is expected to be confirmed Wednesday, and Warren was one of several Democrats arguing against his nomination. Tuesday evening, Warren started reading a 1986 letter from Coretta Scott King on the floor.

That letter was a response to President Reagan's nomination of Sessions as a federal judge. Warren read several passages in which King accused Sessions of working against the intent of the Civil Rights Act of 1964.

She also cited a quote from Sen. Ted Kennedy, D-Mass., who said Sessions in a federal judgeship would be a throwback to a "shameful era," and would be a "disgrace."

Soon after that, she was stopped by presiding officer Sen. Steve Daines, R-Mont., leading to several minutes of discussion between the two senators over what is allowed on the Senate floor. And soon after that, Senate Majority Leader Mitch McConnell, R-Ky., interrupted Warren and said her remarks were out of order.

The specific words McConnell challenged were when Warren said on the floor that Sessions "has used the awesome power of his office to chill the free exercise of the vote by black citizens." Sessions said Warren "impugned the motives and conduct" of Sessions in violation of Senate rules.

Warren argued she was reading King's words. But when Daines agreed with McConnell, Warren appealed the ruling of the chair, and senators voted 49-43 that Daines' ruling was correct.

Sen. Kamala Harris, D-Calif., then called for a vote on whether Warren could continue. But the Senate voted 43-50 against that proposal, effectively locking Warren out of the rest of the debate.

Senate Republicans then rejected a Democratic proposal to insert the text of the full King letter into the record of the day's proceedings.

Sen. Jim Risch, R-Idaho, said Warren violated a clear rule that has been in the Senate for decades, and said it doesn't matter that Warren was simply reading from a letter.

Warren was left fuming over McConnell's interruption over Twitter.

I will not be silent about a nominee for AG who has made derogatory & racist comments that have no place in our justice system. — Elizabeth Warren (@SenWarren) February 8, 2017

I spoke out about @SenatorSessions – until @SenateMajLdr McConnell decided to silence me. https://t.co/qbty7x0iLl — Elizabeth Warren (@SenWarren) February 8, 2017



Warren and Daines had a lengthy back-and-forth when she was first interrupted.

"The senator is reminded that it is a violation of Rule 19 of the standing rules of the Senate to impute to another senator or senators any conduct or motive unworthy or becoming a senator," Daines said.

"Mr. President, I don't think I quite understand," Warren said. "I'm reading a letter from Coretta Scott King to the Judiciary Committee from 1986 that was admitted into the record. I'm simply reading what she wrote about what the nomination of Jeff Sessions to be a federal court judge meant, and what it would mean in history for her."

At that, Daines seemed to back off some.

"This is a reminder, not pertinent necessarily to what you just shared," he said. "However, you stated that a sitting senator is a disgrace to the department of justice..."

"I think that may have been Sen. Kennedy..." she said. "Although I would be glad to repeat it in my own words."

"The rule applies to imputing conduct or motive through any form or voice to a sitting senator," Daines said. "The form of words includes quotes, articles, or other materials."

"So quoting Sen. Kennedy calling then-nominee Sessions a disgrace is a violation of Senate rules? It was certainly not in 1986," Warren said.

"In the opinion of the chair, it is. The senator is warned."

Warren then asked if Senate rules say she can't describe public views and decisions of Sessions.

"The chair has not made a ruling in respect to the senator's comments," Daines said. "The senator is following process and tradition by reminding the senator from Massachusetts of the rule."

"Can I continue with Coretta Scott King's letter?" she asked.

"The senator may continue," Daines said.

Democrats have continued to link Sessions to allegations from three decades ago that his actions as a U.S. attorney in Alabama hurt black voters. Republicans have said Sessions was only working to implement the law at the time, and have rejected allegations that he is a racist.

Warren was just one of many Senate Democrats who were set to talk on the floor all night and into the morning against Sessions, who is expected to be confirmed Wednesday evening.