‘Going to be practical’: Sen. Markwayne Mullin speaks out after being named Noem’s replacement at DHS

The spotlight is now on Republican Sen. Markwayne Mullin as the Oklahoma lawmaker is poised to take over the Department of Homeland Security following Kristi Noem’s controversial tenure and firing on Thursday.

Mullin, 48, has no law enforcement experience but has been a staunch supporter of President Donald Trump’s policies on immigration and law enforcement.

Mullin told ABC News’ Rachel Scott and other reporters shortly after the news broke that he was completely caught off guard when Trump called him about the announcement and hadn’t yet talked to his wife.

“I am super excited about this opportunity,” he said.

“My focus is to keep the homeland secure,” he added.

Mullin will need to be confirmed by the Senate.

He said he is ready to “try to earn everybody’s vote,” including those of Democrats.

“If they have real concerns I’m going to listen to it, I’m going to be practical,” he said.

From business owner to Congress

Mullin has been a member of Congress since 2013, with four years as a senator.

He was born and raised in Oklahoma and member of the Cherokee Nation. Mullin dropped out of college at age 20 to run his father’s plumbing business.

He would eventually earn an associate’s degree from the Oklahoma State University Institute of Technology, making him the only current sitting senator without a bachelor’s degree.

Mullin was a professional mixed martial arts fighter for a brief period in 2006 and 2007.

Mullin would expand his business to other ventures including real estate and agriculture and hosted a radio show on home improvement.

In 2012, Mullin won his first election for Oklahoma’s 2^nd Congressional District with the slogan “A rancher. A businessman. Not a politician.”

He remained the owner of his businesses while a member of the House until 2021.

Mullin championed hard conservative policies during his tenure in the House, including opposing abortion rights, relaxing gun control laws and supporting Trump’s tax cuts.

Mullin champions Trump’s message

He was a vocal supporter of Trump and echoed the president’s baseless claims that the 2020 election was stolen and rigged.

Mullin was inside the House Chamber during the Jan. 6, 2021 attack on the U.S. Capitol by Trump supporters and was seen making makeshift barricades to prevent the rioters from getting in. He continued to push Trump’s baseless election claims following the attack.

“It’s going to be very hard to convince me that Joe Biden received more votes than any other president in history,” Mullin said during an August 2022 Senate candidate debate.

“More and more, we’re finding more details out from different states who are doing a deep dive and are saying this election had a lot more irregularities than we thought,” he added.

There is no evidence of widespread fraud in the 2020 election.

Several audits, probes and lawsuits have determined that the count that gave Biden the win was accurate and the election was conducted properly.

Mullin was a vocal critic of President Joe Biden during his time in the White House and came out against the president’s student loan forgiveness plan. Mullin introduced two resolutions to impeach Biden, which never passed.

In 2022, Mullin won a special election to finish the term retiring GOP Sen. Jim Inhofe. Over the last three years, Mullin continued to push for his conservative policies and when Trump was reelected in 2024, the senator championed the Trump administration’s messaging and policies.

Mullin goes viral in heating moment with union leader

A tense meeting at during a November 2023 Health, Education, Labor and Pensions Committee hearing went viral after Mullin stood up from his seat and appeared to prepare to physically fight Teamsters Union President Sean O’Brien.

O’Brien and Mullin had been engaged in a back and forth on social media where the union leader called the senator a “clown” and a “fraud.”

Mullin read the posts during the hearing and called out O’Brien.

“Sir, this is a time, this is a place. You want to run your mouth? We can be two consenting adults — we can finish it here,” the senator said.  

“OK, that’s fine. Perfect,” O’Brien responded. 

“You want to do it right now?” Mullin asked. 

“I’d love to do it right now,” O’Brien said. 

“Well stand your butt up then,” Mullin replied.

Sen. Bernie Sanders, I-Vt., pleaded for everyone to calm down.

Mullin later told reporters that he has “no beef” with O’Brien and was simply responding to O’Brien’s tweets calling for a fight.

“People have been fighting for a long time. I mean, go back to the 1800s …. It was legal to do duels. If you have a difference, you have a difference,” Mullin said. “I didn’t start it.”

Mullin and O’Brien appeared to put their argument behind them and appeared in a Facebook video together last year promoting the nomination of Labor Secretary Lori Chavez-DeRemer. 

This week Mullin was on the hot seat on Tuesday after he initially told reporters, “This is war, and we’re taking out the threat,” after asked about the U.S. and Israeli army attacks on Iran before backtracking and saying, “We haven’t declared war.”

What happens to Mullin seat if confirmed

If Mullin becomes the new Homeland Security secretary and resigns his seat, then Oklahoma’s governor will temporarily appoint someone to fill his spot but will not need to call a special election, since Mullin’s Senate seat is already up for election this year. 

According to Oklahoma state statute, the governor of Oklahoma appoints someone to take the senator’s place within 30 days of the seat becoming vacant.  

The statute also says that “a person who is a prospective appointee shall submit to the Secretary of State an oath affirming that the person will not file as a candidate for the office when it next appears on the ballot.” 

Because the Senate seat was already scheduled to be “filled for a full term” during the next election, according to state statute, “the candidate elected to the office at the regularly scheduled election shall be deemed to also have been elected to fill the vacancy and shall be eligible to assume the office upon the official certification of the election by the State Election Board.”

Oklahoma Gov. Kevin Stitt, in a statement to ABC News, described Mullen as a “fighter” and said he plans to appoint a “strong, small government conservative voice,” without saying who he is thinking of appointing. 

The Oklahoma State Board of Elections referred ABC News to the office of the Governor.  

The filing deadline for the Senate primary and other offices is April 3 with the primary set for June 16.