As the Senate was debating the nomination of Jeff Sessions to be the new attorney general, Senator Elizabeth Warren spoke in opposition, and tried to read a letter written by Corretta Scott King (the wife of Dr. Martin Luther King, Jr.). Mrs. King wrote the letter in 1986 in opposition to Sessions being considered for a position as a federal judge (a position the Senate denied him).
But the Majority Leader of the Senate decided that the truth about Sessions must be prevented from being revealed, and he accused Warren of impugning the conduct or motives of a fellow senator. He refused to allow Warren to continue reading the letter, and called for a vote of senators to prevent her from doing so. On a 49 to 43 party line vote, Warren was refused the ability, not only to read the letter, but to speak at all on the Sessions nomination -- a shameful action by Republican senators.
Here is Mrs. King's 1986 statement that Republicans didn't want to be made public:
NOTE -- After Senator Warren was silenced, Senator Jeff Merkley took the floor and read the letter without interruption. McConnell and his GOP cohorts did nothing after being so roundly criticized (in both the mainstream and social media) for stopping Warren.