Kristi Noem left the Department of Homeland Security on March 5, 2026, after President Trump announced he would replace her with Sen. Markwayne Mullin.
Trump said he would tap Sen. Markwayne Mullin of Oklahoma to lead DHS, and multiple outlets reported the move as the president privately expressed frustration with Noem after her Senate testimony, according to ABC News and NBC News.
Noem’s tenure at DHS included high-profile oversight moments. Politico reported that an internal DHS watchdog said Noem was “obstructing our work,” and her two-day appearance before Congress was described as contentious in coverage collected by AP’s Kristi Noem hub.
Her DHS biography, last updated March 24, 2026, notes her background as a South Dakota rancher and that she served as homeland security secretary; the department’s site lists her as having taken the role in 2025 before her departure in March 2026.
Political outlets tracked reactions from Capitol Hill. NBC News reported the March 5, 2026 announcement and said the president had made calls to fellow Republicans about the change, while ABC News also covered the firing and Mullin’s selection.
What led to the shake-up, according to reporting, was a mix of Noem’s Senate testimony and internal tensions inside DHS; Politico’s coverage cited the watchdog finding and described strained relations between Noem and career officials.
Democrats were already urging DHS for election-security funding ahead of the midterms, a separate development that places agency leadership and policy priorities under added scrutiny.
Sen. Markwayne Mullin’s own confirmation process and the practical steps for a transition were expected to follow the president’s announcement, according to television and print coverage at the time.
Sources
- ABC News — reported the president’s announcement and Mullin as the pick.
- NBC News — reported the March 5, 2026 firing and described the president’s private frustration after testimony.
- Politico — reported the internal DHS watchdog finding that Noem was “obstructing our work” and detailed contentious Senate testimony.
- DHS.gov — Noem’s official DHS biography and role listing, last updated March 24, 2026.
