On Tuesday, Senate Majority Leader Mitch McConnell objected to Senator Elizabeth Warren’s speech given on the Senate floor against Jeff Sessions.

The issue at the center of the objection: a letter written by Coretta Scott King, Martin Luther King Jr.’s widow.

McConnell invoked the little-used Rule XIX, which states that Senators should not “impute to another Senator or to other Senators any conduct or motive unworthy or unbecoming a Senator.”

He argued that Warren broke that rule when she read the following from King’s letter: “Mr. Sessions has used the awesome power of his office to chill the free exercise of the vote by black citizens.”

Sen. Steve Daines of Montana, who was presiding at the time, agreed with McConnell, ruling her in violation of order.

“I am surprised that the words of Coretta Scott King are not suitable for debate in the United States Senate,” Warren said in response.

READ CORETTA SCOTT KING’S FULL LETTER HERE

A vote was then held on Warren’s appeal of the ruling, with Republicans winning the vote and therefore disbarring Warren from continuing to speak, though Democrats have asked that Warren still be allowed to speak anyway.

“It’s a sad day in America when the words of Martin Luther King Jr.’s widow are not allowed on the floor of the United States Senate,” Donna Brazile, interim chairwoman of the Democratic National Committee, said after the vote. “Let Elizabeth Warren speak. The American people deserve to hear how Jeff Sessions is an extremist who will be a rubber stamp for this out-of-control Trump presidency.”

Standing in solidarity with Warren, Sen. Jeff Merkley managed to read portions of the same letter written by King without any interruption a few hours later.

The Democrats have been attempting to hold the Senate floor for 24 hours in protest of Sessions’ nomination, as they did before for the nomination of Betsy DeVos.