Former mixed martial arts fighter and Republican senator Markwayne Mullin is set to become the next head of the United States Department of Homeland Security, following an announcement by Donald Trump on Thursday.

If confirmed by the Senate, Mullin would replace Kristi Noem, whom Trump said will instead take on a diplomatic security role tied to a new Western Hemisphere initiative.

The move signals a likely continuation—and possibly intensification—of Trump’s hardline immigration policies.

Trump Backs Loyal Ally for Homeland Security Role

Announcing the nomination on his social media platform Truth Social, Trump praised Mullin as someone who would strongly enforce border security and combat crime linked to illegal immigration.

According to Trump, Mullin will focus on strengthening the U.S. border, tackling migrant-related crime, and curbing the flow of illegal drugs into the country. The president framed the nomination as part of a broader effort to restore security and reinforce immigration enforcement.

However, Mullin cannot assume office immediately. Like most cabinet-level positions, his nomination must first be approved by the U.S. Senate through a confirmation vote.

Why Kristi Noem Is Being Replaced

Trump’s decision to move Noem out of the Homeland Security role reportedly followed growing dissatisfaction with how immigration initiatives were being implemented.

In recent days, Noem faced criticism during congressional hearings, where lawmakers from both major parties questioned aspects of the administration’s immigration strategy.

Despite the controversy, Trump indicated that Noem would remain within his administration. He said she would serve as a special envoy for a new initiative called the “Shield of the Americas,” which is aimed at strengthening regional security cooperation across the Western Hemisphere.

Markwayne Mullin’s Political Background

Mullin, a Republican from Oklahoma, has built a reputation as one of Trump’s most loyal allies in Congress.

Before joining the Senate in 2023, Mullin served for a decade in the U.S. House of Representatives. Outside politics, he is known as a rancher and business owner.

He also holds a historic distinction: Mullin is the second citizen of the Cherokee Nation to serve in the U.S. Senate.

Currently, he sits on several influential committees, including:

• Senate Armed Services Committee

• Senate Appropriations Committee

• Senate Health, Education, Labor and Pensions Committee

  
  
  

• Senate Indian Affairs Committee

These assignments have given him significant exposure to national security, defense, and domestic policy issues.

Strong Ties to Donald Trump

Mullin’s relationship with Trump has been a defining feature of his political career.

He was among the Republicans who backed Trump’s claims that the 2020 United States presidential election had been stolen, a stance that strengthened his alignment with the MAGA movement.

According to John Thune, Mullin has at times acted as a “Senate whisperer” for Trump, helping explain congressional dynamics to the president and facilitating communication between the White House and lawmakers.

During the 2024 United States presidential election, Mullin also played a key role as a campaign surrogate. He reportedly worked to mobilize Indigenous voters in key battleground states.

Past Controversies and Public Clashes

Despite his influence, Mullin’s career has not been without controversy.

In 2023, he made headlines during a congressional hearing after challenging Sean O’Brien to a physical fight. The confrontation followed a social media post criticizing Mullin.

During the heated exchange, Mullin suggested the two could settle their differences “as consenting adults,” though the situation ultimately de-escalated without violence.

Earlier in his career, Mullin was also investigated over his involvement in family businesses while serving in the House. The House Ethics Committee concluded that he made good-faith efforts to follow the rules but ordered him to repay $40,000 that had been improperly paid.

More recently, in January 2025, Mullin stirred debate after defending Pete Hegseth against allegations of alcohol abuse, accusing fellow senators of hypocrisy over workplace drinking.

What Mullin’s Appointment Could Mean

If confirmed, Mullin would take charge of one of the most powerful agencies in the U.S. government, overseeing border enforcement, immigration services, and national security operations.

His close alignment with Trump suggests that the administration’s strict immigration policies will remain central to the department’s agenda.

The upcoming Senate confirmation process will determine whether Mullin officially steps into the role.

10 Things to Know About Markwayne Mullin

1. He is currently a U.S. senator from Oklahoma

Mullin represents Oklahoma in the U.S. Senate after winning a special election in 2022. He took office in January 2023, succeeding longtime Republican senator James Inhofe.

2. He served a decade in the U.S. House of Representatives

Before moving to the Senate, Mullin represented Oklahoma’s 2nd Congressional District in the House from 2013 to 2023.

3. He is a citizen of the Cherokee Nation

Mullin is an enrolled member of the Cherokee Nation, making him one of the few Native Americans to serve in the U.S. Senate and the second Cherokee citizen ever elected to the chamber.

4. He once worked as a professional mixed martial arts fighter

Long before politics, Mullin competed in professional mixed martial arts and reportedly went undefeated in his short fighting career.

5. He is also a businessman and rancher

Outside politics, Mullin runs several businesses and operates a cattle ranch in Oklahoma. He first took over his family’s plumbing business at age 20 after his father fell ill.

6. He is known as a strong Trump ally

Mullin has long been a loyal supporter of Trump and the MAGA political movement. He also backed Trump’s claims that the 2020 United States presidential election was stolen.

7. He is the only U.S. senator without a bachelor’s degree

Unlike most members of the Senate, Mullin does not hold a four-year university degree. He earned an associate degree in construction technology instead.

8. He gained national attention for challenging a union leader to a fight

In 2023, Mullin made headlines when he confronted Sean O’Brien during a Senate hearing and suggested they settle their dispute physically. The heated exchange drew widespread criticism but did not escalate into violence.

9. He comes from a large family and has six children

Mullin lives in rural Oklahoma with his wife Christie and their six children, including adopted twins.

10. He may soon oversee U.S. homeland security

If confirmed by the Senate, Mullin will lead the Department of Homeland Security, taking over from Kristi Noem, who is being reassigned to a new diplomatic role focused on security cooperation across the Americas.

FAQ

Who is Markwayne Mullin?

Markwayne Mullin is a Republican U.S. senator from Oklahoma, former mixed martial arts fighter, rancher, and business owner. He previously served in the U.S. House of Representatives before joining the Senate in 2023.

Why did Trump nominate Mullin as Homeland Security Secretary?

Trump nominated Mullin because of his strong support for the administration’s immigration and border security policies.

What happened to Kristi Noem?

Kristi Noem is expected to move to a new role as a special envoy for a regional security initiative known as the “Shield of the Americas.”

Does Mullin need Senate approval?

Yes. Like other cabinet nominees, Mullin must be confirmed by the U.S. Senate before assuming the role.

What controversies has Mullin faced?

Mullin has faced criticism for challenging a labor leader to a fight during a congressional hearing and for a past ethics investigation related to his business activities.