By invoking an obscure Senate rule Tuesday night, Senate Majority Leader Mitch McConnell (R-Ky.) effectively silenced Sen. Elizabeth Warren (D-Mass.) as Warren was reading Coretta Scott King's 1986 letter against Sen. Jeff Sessions (R-Ala.). McConnell alleged that Warren had "impugned the motives and conduct of our colleague from Alabama," a violation of the rarely-used Rule 19 of the upper chamber. As a result, Warren was banned from speaking on the Senate floor as long as Sessions — President Donald Trump's attorney general pick — was the topic.
As it turns out, Rule 19 dates back to a different — and perhaps more violent — time in the Senate, The Washington Post reports. In 1902, a fistfight erupted between South Carolina's two Democratic senators after the senior senator, Benjamin Tillman, accused his protégé, John McLaurin, of working with Republicans on some issues. McLaurin had fallen victim to "improper influences," Tillman alleged, prompting McLaurin to storm into the chamber and accuse Tillman of a "willful, malicious, and deliberate lie."
Naturally, the pair started throwing punches. "Efforts to separate the two combatants resulted in misdirected punches landing on other members," Senate historians recalled. Rule 19 was adopted shortly afterward, apparently to keep senators in line (or at least more docile) during floor debates.
"In the time since, the rule has rarely come up," The Washington Post adds. "One instance flagged by Bloomberg's Greg Giroux occurred in 1979, when Sen. Lowell Weicker (R-Conn.) called Sen. John Heinz (R-Pa.) 'an idiot' and 'devious' in a debate on the Senate floor. Heinz reportedly stormed to the front of the room with a rule book and showed him Rule 19. Majority Leader Robert Byrd (D-W.Va.) defused the situation and asked them to shake hands. Other examples are hard to come by."
Read more about the obscure law and its origins at The Washington Post.