On Tuesday night Mitch McConnell invoked part of one of the Senate’s rules of debate—part of Rule 19—to stop Elizabeth Warren from speaking while she was reading a 1986 letter, written by Coretta Scott King, that criticizes attorney general nominee Jeff Sessions’ record on civil rights. The Washington Post notes that this guideline was enacted in 1902 after a fight on the Senate floor. Here, from a book called The American Senate: An Insider’s History, is the context:

An incident in the 1850s inspired consideration about adopting a rule to curb such excesses, but the Senate finally did so only after an ugly episode during a debate in 1902. South Carolina’s “Pitchfork Ben” Tillman accused his South Carolina colleague, John McLaurin, of selling his vote for federal patronage. McLaurin called Tillman a malicious liar. Tillman lunged at him, striking him above the left eye. McLaurin hit Tillman back with an upper-cut to the nose. They were separated by other senators, and the brawl caused consternation throughout political Washington. Senator George Hoar of Massachusetts seized the occasion to propose a rule he long had had in mind: “No senator in debate shall, directly or indirectly or by any form of words impute to another senator or to other senators any conduct or motive unworthy or unbecoming a senator.” Once adopted, senators had the means of instantly quieting raucous or abusive debates.

The rule was created, in other words, to protect senators like Ben Tillman from hearing mean things that would make them so mad they had to punch someone. And Ben Tillman, as it happens, is perhaps the most notorious proponent of racial terrorism in the history of the United States. Here are just a few of the things Tillman said during his horrific political career:

“[We] agreed on on the policy of terrorizing the Negroes at the first opportunity by letting them provoke trouble and then having the whites demonstrate their superiority by killing as many of them as was justifiable.” (Tillman boasted during the same speech that his pistol had been used to execute seven black men in 1876. Source.)

“Lynch law is all we have left.” (Source.)

“The action of President Roosevelt in entertaining that nigger will necessitate our killing a thousand niggers in the South before they learn their place again.” (In reference to Booker T. Washington’s visit to the White House. Source.)

“We of the South have never recognized the right of the Negro to govern white men, and we never will. We have never believed him to be the equal of the white man, and we will not submit to his gratifying his lust on our wives and daughters without lynching him. I would to God the last one of them was in Africa and that none of them had ever been brought to our shores.” (That one was on the floor of the Senate itself. Source.)

Indeed, is it not obvious that we must protect the integrity of Rule 19 to ensure that the Senate continues to be a safe space for Ben Tillman’s successors?