Mullin’s appointment to lead DHS raises questions about future of CISA

Sen. Markwayne Mullin, R-Okla., talks with reporter outside the U.S. Capitol after President Donald Trump selected him to be Department of Homeland Security secretary to replace Kristi Noem on Thursday, March 5, 2026. Tom Williams/CQ-Roll Call, Inc via Getty Images

The Trump administration’s decision to tap Oklahoma Republican Sen. Markwayne Mullin to lead the Department of Homeland Security is drawing mixed reactions inside the department and its Cybersecurity and Infrastructure Security Agency, which employees say has struggled to regain its footing after months of staffing cuts and leadership turmoil.

Trump immediately tapped Mullin after firing Kristi Noem from her post on Thursday. It followed two days of congressional testimony, during which she faced tough questions from both parties on fatal shootings by DHS employees, aggressive immigration tactics and excessive spending on an ad contract that featured her.

In Noem’s tenure as DHS secretary, CISA has seen ...