On Tuesday, a heated exchange between Republican Senator Markwayne Mullin of Oklahoma and Sean O'Brien, the president of the International Brotherhood of Teamsters, almost turned into a fistfight during a Senate hearing on labor unions. Mullin, a former MMA fighter, had challenged O'Brien to a physical fight for charity, but the exchange was eventually brought back to order. Mullin and O'Brien have since apologized for their behavior, sparking a debate over the appropriateness of physical confrontations in the Senate.
