WATCH: Oklahoma senator challenges Teamsters president to a fight during Senate hearing

A Senate hearing escalated into a near brawl on Tuesday when Oklahoma's Republican Sen. Markwayne Mullin asked Sean O’Brien, the president of the International Brotherhood of Teamsters, if he wanted to fight “right now.” The move came after O’Brien, testifying before the Senate Committee on Health, Education, Labor, and Pensions about unions, challenged Mullin, who fought as an MMA fighter prior to coming to Congress, to a fight in June on X, formerly known as Twitter. O’Brien’s social media post called Mullin a “clown” and “fraud” and ended with, “You know where to find me. Anyplace, Anytime cowboy.” The thrust of O'Brien's post challenged Mullin's "self-made" characterizations of his business background. Mullin used his time during questioning to confront O’Brien over the comments. “Sir, this is a time. This is a place. You want to run your mouth? We can be two consenting adults — we can finish it here,” Mullin said. “OK, that’s fine. Perfect,” O’Brien responded to the challenge. "Well, stand your butt up then,” Mullin taunted, with O’Brien telling Mullin to do the same. Committee chairman Sen. Bernie Sanders of Vermont, who was running the hearing, began pleading for them to stop. “This is a hearing and God knows the American people have enough contempt for Congress," Sanders said. “We’re not here to talk about fights, or anything else,” Sanders said. Stream your PBS favorites with the PBS app: https://to.pbs.org/2Jb8twG Find more from PBS NewsHour at https://www.pbs.org/newshour Subscribe to our YouTube channel: https://bit.ly/2HfsCD6 Follow us: TikTok:   / pbsnews   Twitter:   / newshour   Instagram:   / newshour   Facebook: http://www.pbs.org/newshour Subscribe: PBS NewsHour podcasts: https://www.pbs.org/newshour/podcasts Newsletters: https://www.pbs.org/newshour/subscribe