Markwayne Mullin’s Government and Service History Explained As Trump Names Kristi Noem’s Replacement
In a surprise announcement on Thursday, President Donald Trump announced that he will replace Homeland Security Secretary Kristi Noem with Oklahoma Republican Senator Markwayne Mullin, marking one of the most significant cabinet shakeups of his second administration.
Trump revealed the decision in a post on Truth Social, stating that Mullin would become the next Secretary of the Department of Homeland Security beginning March 31, pending Senate confirmation. Noem will leave the position after just over a year in office and instead serve as “Special Envoy for the Shield of the Americas,” a new initiative focused on security cooperation across the Western Hemisphere.
Trump wrote on social media that, “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 of Homeland Security (DHS), effective March 31, 2026. The current Secretary, Kristi Noem, who has served us well, and has had numerous and spectacular results (especially on the Border!), will be moving to be Special Envoy for The Shield of the Americas, our new Security Initiative in the Western Hemisphere we are announcing on Saturday in Doral, Florida. I thank Kristi for her service at ‘Homeland.'”
Noem, the former governor of South Dakota, had served as secretary of homeland security since January 2025, after being nominated by Trump shortly after his return to the White House. The latest controversy with her tenure involved a $220 million advertising campaign aimed at encouraging undocumented immigrants to self-deport.
Trump’s choice to replace Noem, Senator Markwayne Mullin, is a longtime Republican ally who has served in the U.S. Senate since 2023 after previously spending a decade in the House of Representatives. Mullin, a member of the Cherokee Nation and a businessman before entering politics, has built a reputation as a staunch supporter of Trump and a vocal advocate for conservative border security policies.
Mullin, 48, has served as the junior United States senator from Oklahoma since January 2023 after winning a special election to fill the seat vacated by longtime Republican Senator Jim Inhofe. Before entering the Senate, he spent a decade in the House of Representatives representing Oklahoma’s 2nd Congressional District from 2013 to 2023.
His path to politics began in the family business. At age 20, Mullin took over his father’s plumbing company after his father fell ill. The company grew into a successful regional business, helping him build personal wealth and name recognition in eastern Oklahoma. Before running for office, Mullin also hosted a home-improvement radio show in Oklahoma called House Talk, which helped boost his profile with voters across the state. Mullin is an enrolled citizen of the Cherokee Nation and became one of the few Native Americans serving in the U.S. Senate when he was elected in 2022.
In the Senate, Mullin serves on several committees, including Armed Services, Appropriations, Health, Education, Labor and Pensions, and Indian Affairs. If confirmed by the Senate, he would assume leadership of one of the largest federal departments, which oversees agencies including Immigration and Customs Enforcement, the Secret Service, the Coast Guard, and the Federal Emergency Management Agency.
Trump praised Mullin in his announcement, calling him a “highly respected” lawmaker and saying he would continue the administration’s efforts to strengthen border enforcement and national security. The nomination still requires Senate approval, meaning Mullin would likely face hearings before the Senate Homeland Security and Governmental Affairs Committee.
