WASHINGTON, DC - MARCH 24: Former U.S. Sen. Markwayne Mullin (R-OK) and his wife Christie Mullin look on before he is sworn in as the next secretary of the Department of Homeland Security in the Oval Office at the White House on March 24, 2026 in Washington, DC. Mullin takes the helm of DHS during a challenging time as it has been partially shut down since February 14 while lawmakers negotiate reforms for Immigration and Customs Enforcement. (Photo by Chip Somodevilla/Getty Images)