Following a heated exchange on social media, Senator Markwayne Mullin (R-OK) has agreed to a mixed martial arts (MMA) charity cage fight against Teamsters General President Sean O’Brien. The showdown is scheduled for September 30th in Tulsa, Oklahoma.
The feud ignited when O’Brien criticized Mullin online, calling him a "greedy CEO" and a "clown [and] fraud." He taunted Mullin to "Quit the tough guy act" and added, "You know where to find me. Anyplace, Anytime cowboy." Mullin, a former MMA fighter, promptly accepted the challenge via Twitter, proposing the fight be held for a charity of each combatant's choosing.

This online spat follows a previous confrontation during a Senate hearing in March. The two clashed over O'Brien's salary compared to the average Teamster driver's earnings. Mullin questioned O'Brien's contributions, asking what job he had created besides "sucking the paycheck out of somebody else." O'Brien disputed Mullin's figures and the exchange escalated with both men talking over each other and Mullin telling O'Brien to "shut your mouth."

Mullin has accused O’Brien of being a "bully" who tries to intimidate others. He cited past incidents where O’Brien was allegedly suspended for threats against union members. Mullin also criticized O'Brien's stance on right-to-work states like Oklahoma and his advocacy for more "militant" union practices.

As of now, O’Brien has not publicly responded to Mullin’s acceptance of the cage fight challenge.