Sen. Elizabeth Warren, D-Mass., in a Senate committee hearing last year. Pete Marovic/Bloomberg via Getty Images

The words were those of Coretta Scott King, widow of the Rev. Dr. Martin Luther King Jr.

But they resulted in a rarely-invoked Senate rule being used to formally silence Sen. Elizabeth Warren, D-Mass.

On the Senate floor yesterday Warren was reading from a letter Scott King wrote in 1986 objecting to President Ronald Reagan’s ultimately unsuccessful nomination of then-U.S. Attorney Jeff Sessions to a federal district court seat.

King wrote that Sessions used “the awesome power of his office to chill the pre-exercise of the vote by black citizens.”

Now-Sen. Sessions, R-Ala., is President Trump’s nominee for U.S. attorney general. Warren was speaking in the debate leading up to Sessions’ likely confirmation Wednesday.

The offending letter led Senate Majority Leader Mitch McConnell to object to Warren’s remarks, as The Associated Press reported:

Quoting King technically put Warren in violation of Senate rules for “impugning the motives” of Sessions, though senators have said far worse stuff. 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 up.

Now, Warren is forbidden from speaking again on Sessions’ nomination. A vote on Sessions is expected Wednesday evening.