Senator Markwayne Mullin is apparently out for blood in his ongoing feud with a union boss. The freshman congressman has taken to conservative political talk shows, refusing to give up a fight he had sparked with International Brotherhood of Teamsters President Sean O’Brien, a Senate committee witness, during a Tuesday hearing. On one show, Mullin claimed that he “wasn’t afraid of biting” O’Brien if the moment called for it. “I’ll bite 100 percent. In a fight, I’m gonna bite. I’ll do anything.