Noem Out, Mullin In: Trump Fires His DHS Secretary & Picks a Former MMA Fighter to Secure America

It happened fast — and it happened today. President Donald Trump announced Thursday afternoon on Truth Social that Homeland Security Secretary Kristi Noem is out, and that Oklahoma Senator Markwayne Mullin will become the next Secretary of Homeland Security, effective March 31, 2026. Noem is being reassigned rather than dismissed outright — Trump framed her departure as a promotion to a newly created role as Special Envoy for the Shield of the Americas — but the political reality is clear: Noem's tenure at DHS is over, and the president lost confidence in her after a bruising week on Capitol Hill. Why Noem Was Fired Kristi Noem had been in an increasingly precarious position for weeks — but the final straw came during her congressional testimony this week, which went badly enough to directly anger the president. Two lines of criticism converged on her simultaneously. The first was a $220 million taxpayer-funded advertising campaign that DHS had run under her leadership — an expenditure that drew withering questions from both Republicans and Democrats, with Republican Senator John Kennedy among the most pointed critics. The second was the broader handling of Trump's immigration enforcement agenda — including the deaths of two American citizens, Renee Good and Alex Pretti, who were killed in separate incidents by federal immigration agents in Minnesota in January. The combination of bipartisan criticism, embarrassing testimony, and a personal relationship between Noem and former Trump aide Corey Lewandowski that had generated its own headlines proved too much. Trump made his decision Thursday — and Noem learned about it at roughly the same time the rest of the world did. Who Is Markwayne Mullin? Markwayne Mullin, 48, is one of the more colourful figures in the United States Senate — and that is saying something. Born in Tulsa on July 26, 1977, the youngest of seven children, he grew up on his family's ranch in Westville, Oklahoma — where he and his family still live today. He is, by background, a licensed plumber who took over his family's plumbing business before pursuing a career in politics. He is also a former professional mixed martial arts fighter — a detail Trump highlighted prominently in his Truth Social announcement, describing Mullin as someone who will bring a fighter's mentality to the border. He served for a decade in the House of Representatives before winning a 2023 special election to the Senate seat vacated by James Inhofe — making him the only Native American currently serving in the United States Senate. In the Senate, Mullin has been one of Trump's most reliable and aggressive allies. He serves on the Armed Services, Appropriations, Health, Education, Labor and Pensions, and Indian Affairs committees. Senate Majority Leader John Thune described Mullin as Trump's "Senate whisperer" — someone capable of explaining the legislature's positions to the president and successfully influencing his thinking. Mullin was a key surrogate for Trump during the 2024 campaign, focusing specifically on outreach to indigenous voters in battleground states. He was among the first Senate Republicans to defend Pete Hegseth during his confirmation hearing, attacking fellow senators who raised concerns about Hegseth's conduct. He also has a well-publicised record of confrontation — most notably his challenge to Teamsters president Sean O'Brien to a fight during a 2023 congressional hearing after O'Brien posted critical remarks about him on social media. The Confirmation Battle Ahead Mullin will need Senate confirmation to permanently assume the role — and the path is not straightforward. Most Senate Democrats are expected to oppose the nomination, and Republicans hold only a narrow majority in the chamber. The administration will need near-unanimous GOP support to secure confirmation. Under federal law governing executive branch vacancies, however, Mullin can serve as acting DHS Secretary while his nomination is formally pending — meaning he can take the reins on March 31 without waiting for the Senate to act. When NBC News caught up with Mullin in a Capitol hallway shortly after Trump's announcement, his response was characteristically understated: "I found out just before you guys did." What Mullin Inherits at DHS The Department of Homeland Security is one of the largest and most complex agencies in the federal government — overseeing US Customs and Border Protection, Immigration and Customs Enforcement, the Transportation Security Administration, the Secret Service, and FEMA. Under Noem, the department presided over what the administration describes as the most aggressive immigration enforcement operation in American history — with over two million people self-deporting in 2025 under the pressure of Trump's mass deportation agenda. Mullin inherits that operation in full swing — and with the Iran conflict now adding a significant domestic security dimension to DHS's responsibilities, including heightened threat assessments for Iranian-linked actors inside the United States, the portfolio he is inheriting is more demanding than at any point since the department's founding after September 11. Noem's New Role: Shield of the Americas Noem's reassignment as Special Envoy for the Shield of the Americas is not nothing — but it is a clear demotion from one of the most powerful cabinet positions in Washington. The Shield of the Americas is a new Western Hemisphere security initiative the Trump administration plans to formally unveil Saturday in Doral, Florida. Details are limited, but the initiative is described as focused on border enforcement and regional security cooperation across the Western Hemisphere. Noem took the stage at a DHS event moments after Trump's announcement and made no immediate mention of her ouster — speaking calmly from behind a podium as if nothing had happened. It was, in its way, the most Kristi Noem thing she could possibly have done. For the latest US political and national security coverage, follow digital8hub.com.