Trump Replaces Homeland Security Secretary Noem, Nominates Senator Mullin

President Donald Trump announced on Thursday, March 5, 2026, that he is replacing Homeland Security Secretary Kristi Noem with Oklahoma Senator Markwayne Mullin. The decision follows scrutiny of Noem’s leadership and immigration enforcement tactics during congressional hearings earlier this week.

Noem’s Tumultuous Tenure

Noem, the first Cabinet secretary to leave during Trump’s second term, faced criticism regarding the implementation of the administration’s hard-line immigration agenda. Specifically, she was questioned about the handling of immigration enforcement operations, including a controversial operation in Minneapolis that led to the deaths of two American citizens . She too received criticism for departmental spending, including millions allocated to advertising and the purchase of recent jets with luxurious amenities .

During congressional hearings, Republicans and Democrats alike raised concerns about “government waste” and the approval process for departmental advertising .

Mullin’s Nomination and Confirmation Process

Senator Markwayne Mullin, a Republican from Oklahoma, has been nominated to replace Noem. Trump stated on social media that Mullin “will function tirelessly to Keep our Border Secure, Stop Migrant Crime…and, Build AMERICA SAFE AGAIN” . Mullin expressed his appreciation for the nomination and affirmed his commitment to supporting the President’s mission to safeguard the nation .

While Mullin requires Senate confirmation, a federal law allows him to serve as acting homeland security secretary while his nomination is pending . Mullin indicated he was unsure of the timeline for his confirmation .

New Role for Noem

President Trump announced that Kristi Noem will be appointed as a “special envoy for The Shield of the Americas,” a new security initiative focused on the western hemisphere . Noem thanked Trump for the new appointment and highlighted what she considered her accomplishments at the Department of Homeland Security .

Immigration Enforcement and DHS Operations

Mullin will lead the third-largest department in the government, responsible for executing Trump’s immigration agenda. During the first year of the Trump administration, immigration enforcement was characterized by high-profile operations, often led by Border Patrol commander Gregory Bovino, reporting directly to Noem . These operations, frequently publicized on social media, sometimes resulted in clashes with activists and protesters .