President Donald Trump says Oklahoma Senator Markwayne Mullin will take over the Department of Homeland Security, replacing Kristi Noem later this month. The move puts a first-term senator into one of the most demanding Cabinet jobs in Washington. It also puts a former fighter, plumber, and rancher in charge of an agency responsible for border security, immigration enforcement, and disaster response.
Trump made the announcement Thursday in a social media post. He said Mullin would become secretary of the United States Department of Homeland Security effective March 31. He described the Oklahoma Republican as a “MAGA warrior” and predicted he would be a “spectacular” leader for the department.
( @realDonaldTrump – Truth Social Post )
( Donald J. Trump – Mar 05 2026, 1:41 PM ET )
I am pleased to announce that the Highly Respected United States Senator from the Great State of Oklahoma, Markwayne Mullin, will become the United States Secretary o… pic.twitter.com/ciyOWvpfMj
— Donald J Trump Posts TruthSocial (@TruthTrumpPost) March 5, 2026
The job is one of the largest in government. It has more than 260,000 employees work across the department.
Mullin’s path also looks nothing like the usual Washington résumé, says USA Today.
He grew up in Westville, a small town in eastern Oklahoma, where the family business was plumbing. When his dad became seriously ill in the late 1990s, Mullin left college. He stepped up to keep the company going. He was 20.
Over time the business grew. Mullin Plumbing expanded into one of the region’s larger service companies. New ventures followed in environmental services, construction projects, and a steakhouse in Stilwell. Family members stayed involved. The work stayed local.
Markwayne Mullin took over his father’s plumbing business, Mullin Plumbing, at the age of 20 in 1997 after his father fell ill. https://t.co/ARxUQSXSv4
— The Intellectualist (@highbrow_nobrow) January 23, 2025
Politics came later.
In 2012, Mullin ran for Congress. He won a seat representing Oklahoma’s 2nd District. He held that seat for a decade before running for the Senate a decade later. He took office in 2023 after winning a special election.
One detail stands out Mullin is an enrolled citizen of the Cherokee Nation. He is the first tribal citizen to serve in the Senate in nearly twenty years. The last had been Ben Nighthorse Campbell who retired in 2005.
Before Congress, though, there was another chapter with a rather unexpected career choice.
Mullin briefly fought in mixed martial arts. His professional record — five fights, five wins. Undefeated. The experience stuck to his political brand. Supporters sometimes point to it when describing his direct, combative style.
Working through the weekend with President Donald J. Trump.
It’s always an honor to be in the Oval Office— I never take this opportunity to serve Oklahoma for granted. 🇺🇸 pic.twitter.com/x2M0EvuBcR
— Markwayne Mullin (@SenMullin) November 8, 2025
And, Trump has always had an ally in him.
After the 2020 election, Mullin repeated claims that the vote had been stolen, even though the courts said otherwise. In Congress he backed a resolution calling for Trump’s two impeachments to be removed from the official record.
In 2020 he co-introduced the “Protect Women’s Sports Act” with then-Representative Tulsi Gabbard. The proposal wanted to limit participation in women’s sports based on sex at birth rather than gender identity.
And then, the infamous story of when Mullin was caught lying to make Trump look good. During the longest government shutdown in 2025, he took to social media making it seem as if Trump had been working through the weekend to resolve the issues. In the meantime, Trump had been golfing it up at Mar-a-Lago.
‘HUMBLING’: Senator Markwayne Mullin reacts to President Trump picking him as the new Department of Homeland Security Secretary.
“I had to call my dad… It’s just pretty humbling when you start thinking about it. A little kid from west Oklahoma gets to serve in the president’s… pic.twitter.com/ByaKUp6PPa
— Fox News (@FoxNews) March 5, 2026
Those positions made him a visible figure among Trump-aligned Republicans in Congress.
On the personal side, he also seems to have struck it lucky. Married to his high school sweetheart, Christie, Mullin is the father of six children. The family still lives near Westville on ranch land tied to his childhood. Campaign ads often showed cattle, open fields, and pickup trucks.
When Trump called about the DHS job, Mullin later described the moment in simple terms during a television interview.
“I had to call my dad,” he said. “It’s pretty humbling when you start thinking about it. A little kid from west Oklahoma gets to serve in the president’s cabinet.”
