GOP Senator Markwayne Mullin Challenges Teamsters President Sean O'Brien to Physical Confrontation at Senate Hearing

Republican Senator Markwayne Mullin challenged the president of the International Brotherhood of Teamsters, Sean O'Brien, to a physical fight during a Senate hearing on labor unions. The confrontation stemmed from a previous heated exchange between the two, with Mullin holding up printed versions of O'Brien's tweets criticizing him. The situation escalated as both men stood up, but was eventually diffused by Senator Bernie Sanders. The exchange ended with insults being exchanged, and Mullin later stated that he accepted the challenge because O'Brien had challenged him first.