Sen. Markwayne Mullin's Cabinet nomination advanced to the Senate floor Thursday despite opposition from Homeland Security and Governmental Affairs Committee Chairman Rand Paul (R-Ky.). Why it matters: The 8-7 committee vote puts Mullin an important step closer to being confirmed to succeed Kristi Noem as Homeland Security secretary when Noem steps down at the end of the month. Paul voted "no, while Sen. John Fetterman (D-Pa.) voted in favor.Otherwise, the vote split along party lines. State of play: The vote followed a vitriolic hearing on Wednesday that opened with Paul challenging Mullin to "tell me to my face" why Paul deserved an assault that left him with broken ribs."You have never had the courage to look me in the eye and tell me the assault was justified," Paul said, referring to comments Mullin made at a town hall, where he also called Paul a "freakin' snake.""And while you're at it, explain to the American public why they should trust a man with anger issues," Paul added.Democrats also expressed concerns about whether Mullin was temperamentally suited to the job, as well as questioning his experience.Zoom in: Mullin's hearing also shed little light on how to end the DHS shutdown, now in its second month. Democrats remain dug in on demands for statutory changes to ICE and Border Patrol.And, as Axios' Hans Nichols and Stephen Neukam report, Mullin's testimony didn't alter that dynamic."I don't think his nomination increases the likelihood of a compromise, because he stood pretty firm against the kinds of reforms that Americans are demanding," Sen. Richard Blumenthal (D-Conn.), told Axios.Yes, but: Paul still likely has the votes to be confirmed. What we're watching: It's unusual for a Cabinet nominee to advance to a floor vote without support from the chairman of the committee of jurisdiction. If Paul ultimately votes against Mullin on the floor, he would be the only senator in modern history to oppose a fellow senator nominated by a president of his own party.Editor's note: This story has been updated with additional reporting.