Tom Williams/CQ-Roll Call, Inc via Getty ImagesA Senate HELP Committee hearing descended into chaos Tuesday as Sen. Markwayne Mullin (R-OK), a former Mixed Martial Arts fighter, challenged Teamster boss Sean O’Brien to a physical fight during the latter’s testimony. Mullin read aloud a June post by O’Brien: “Quit the tough guy act in these Senate hearings. You know where to find me. Any place, Anytime cowboy.” Mullin followed it up by saying, “This is a time, this is a place. We can be two conse