Senate Majority Leader Mitch McConnell shut down Massachusetts Sen. Elizabeth Warren during a Senate floor speech on Tuesday, accusing the Democrat of violating Senate rules by criticizing their colleague and attorney general nominee, Alabama Sen. Jeff Sessions.

Warren was warned early on in her remarks by Montana Sen. Steve Daines, the Republican overseeing the floor speeches, after she quoted Coretta Scott King, the late widow of Martin Luther King, Jr.

Warren quoted King asserting that Sessions had “exhibited so much hostility to the enforcement” of voting rights laws for blacks.

Daines struck his gavel and reprimanded Warren, who is one of a handful of Democrats who plan an all-night Senate floor session to oppose the Trump nominee.

“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.

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“Mr. President, I don’t think I quite understand,” Warren replied. “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.”

“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…although I would be glad to repeat it in my own words,” said Warren, referring to remarks she read earlier from late Massachusetts senator Ted Kennedy.

Daines said that Rule 19 “applies to imputing conduct or motive through any form or voice to a sitting senator.”

“The form of words includes quotes, articles, or other materials.”

Around 20 minutes later, McConnell interrupted Warren’s speech to invoke Rule 19.

“The senator has impugned the motives and conduct of our colleague from Alabama as warned by the chair,” said McConnell.

“Senator Warren, quote, said Senator Sessions has ‘used the awesome power of his office to chill the free exercise of the vote of black citizens.’ I call the senator to order under the provisions of Rule 19.”

Warren protested.

“Mr. President, I am surprised that the words of Coretta Scott King are not suitable for debate in the United States Senate. I ask leave of the Senate to continue my remarks.”

McConnell objected to Warren’s request and Daines ordered her to take her seat.

Warren appealed the ruling and called for a quorum vote to delay the proceedings.

Despite Democrats’ protest speeches, Sessions is expected to be approved as attorney general on Wednesday.

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