Watch: GOP senator challenges Teamsters president to fight at Senate hearing

Republican Sen. Markwayne Mullin of Oklahoma challenged the president of the International Brotherhood of Teamsters to a fight in a tense moment during a Senate hearing on Tuesday. The confrontation occurred during a hearing on labor unions held by the Senate Committee on Health, Education, Labor and Pensions. Sean O’Brien, the head of one of the nation’s largest and most influential unions, was appearing as a witness. Source