Senator Elizabeth Warren earned a rare rebuke by the Senate for quoting Coretta Scott King

UPDATE 6:28 a.m. Feb. 8:

Sen. Elizabeth Warren's speech and silencing on the Senate floor has sparked outrage on Twitter from her Democratic colleagues and supporters. 

Warren was told she was violating a Senate rule against "impugning the motives" of Sen. Jeff Sessions. She had been reading a letter from Coretta Scott King, Dr. Martin Luther King's Jr.'s widow. 

The letter outlines systemic obstacles to voting that black Americans faced, USA Today reports. King accused Sessions of worsening the situation by prosecuting three voting rights advocates.  

#LetLizSpeak quickly trended on Twitter.

Sen. Kamala Harris (D-CA) said the process demeaned King's memory.

Feminist groups tracked which senators voted to silence Warren.

Warren herself wasn't pleased by the move.

WATCH | Sen. Cory Booker (D-NJ) praised Warren, saying, "God bless her for standing up."

WATCH | But Sen. James Risch (R-ID) condemned Warren's speech, saying the rules were clear. 

ORIGINAL STORY:

Senator Elizabeth Warren earned a rare rebuke by the Senate when she quoted Coretta Scott King on the Senate floor while debating Jeff Sessions' nomination. 

The Massachusetts Democrat mistook the Chamber's arcane rules by reading a three-decade-old letter from Dr. Martin Luther King's widow which dated back to Senator Jeff Sessions' failed judicial nomination three decades ago. 

King wrote that when acting as a federal prosecutor, Sessions used his power to "chill the free exercise of the vote by black citizens." By quoting King, Warren was in violation of Senate rules for "impugning the motives" of Sessions, though senators have said far worse statements. And Warren was reading from a letter that was written 10 years before Sessions was even elected to the Senate. Still, top Senate Republican Mitch McConnell invoked the rules. After a few parliamentary moves, the GOP-controlled Senate voted to back him. 

Now, Warren is forbidden from speaking again on Sessions' nomination, when a vote on Sessions is expected on Wednesday evening. Democrats seized on the opportunity to charge that Republicans were muzzling Warren, sparking liberals to take to Twitter to post the King letter in its entirety. Warren argued: "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."

Warren also read the letter outside the Senate and posted a video to Facebook.

Warren was originally warned after reading from a statement by former Sen. Edward Kennedy, D-Mass., that labeled Sessions a disgrace. Democrats pointed out that McConnell didn't object when Sen. Ted Cruz, R-Texas, called him a liar in 2015. 

The episode was followed by complaints by Senate veterans, including its most senior Republican, Orrin Hatch of Utah, about how the Senate is too partisan. 

Here's how a few people felt regarding Warren's rebuke: 

The Associated Press contributed to this report