Kristi Noem Out as Homeland Security Secretary After Turbulent Tenure; Trump Taps Sen. Markwayne Mullin as Successor

March 5, 2026 - Washington, D.C. - President Donald Trump announced Thursday that Homeland Security Secretary Kristi L. Noem will leave her post at the end of the month, ending a tenure marked by sweeping immigration crackdowns, the dismantling of FEMA, and persistent controversy over the direction of the Department of Homeland Security.

Trump said Noem will be replaced by Sen. Markwayne Mullin (R‑Okla.), a first‑term senator and longtime ally of the administration. The transition will take effect March 31, 2026.

The announcement came in a social media post in which Trump praised Noem's work while outlining her next role in the administration.

"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," Trump wrote. "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."

A Tenure Defined by Aggressive Immigration Policy

Noem's 14 months at DHS were among the most polarizing of the Trump administration's second term. She oversaw:

- Large‑scale removals of undocumented immigrants, including expanded interior enforcement operations.

- The dismantling of FEMA, with disaster‑response responsibilities redistributed across DHS and the Pentagon.

- A series of high‑profile border actions, including rapid‑deployment units and expanded use of military support.

Supporters credited her with restoring what they described as "operational control" of the southern border. Critics accused her of overreach, destabilizing emergency management, and pushing DHS into unprecedented territory.

Her appearance before the House Judiciary Committee on March 4, where she defended her record amid intense questioning, now appears to have been her final major hearing as secretary.

Mullin's Appointment Signals Continuity - and a Shift in Style

Sen. Markwayne Mullin, a former MMA fighter and businessman, has been a vocal supporter of Trump's border and national‑security agenda. His move from the Senate to DHS is expected to maintain the administration's policy direction while bringing a different public tone to the department.

Mullin has served on committees overseeing intelligence, homeland security, and military affairs, and has been a frequent defender of Trump's approach to immigration enforcement.

His confirmation process is expected to move quickly in the Senate, where Republicans hold a narrow majority.

Noem's New Role: "The Shield of the Americas"

Trump said Noem will become Special Envoy for The Shield of the Americas, a new Western Hemisphere security initiative the administration plans to unveil this weekend in Doral, Florida.

While details of the initiative remain limited, officials have described it as a regional framework focused on:

- Counter‑cartel operations

- Migration deterrence

- Intelligence sharing

- Maritime and border security partnerships

The envoy role is expected to involve extensive diplomatic travel and coordination with Latin American governments.

What Comes Next

Noem's departure marks the third Cabinet‑level change in the past six months, reflecting the administration's rapid restructuring of national‑security and immigration operations. Mullin's arrival at DHS is likely to reinforce Trump's priorities while potentially recalibrating the department's public posture.

With the administration preparing to roll out its new hemispheric security strategy, the shift at DHS comes at a pivotal moment for U.S. border policy, regional diplomacy, and domestic emergency management.