‘Shut your mouth’: Republican senator and Teamsters leader in fiery clash

Markwayne Mullin, a former MMA fighter, argues with union's Sean O'Brien as Bernie Sanders seeks order in Senate hearing

A Republican senator who once had to reassure voters he didn't think he was Rambo" and was a mixed martial arts fighter before entering politics got into a vocal brawl with a union boss during a public congressional hearing, saying: You need to shut your mouth."

Markwayne Mullin of Oklahoma exchanged verbal fire with Sean O'Brien, president of the Teamsters, during a hearing staged on Wednesday by the Senate health, education, labor and pensions committee.