(FILES) US Senator Markwayne Mullin (R-OK), nominee to be Secretary of Homeland Security, testifies during a Senate Committee on Homeland Security and Governmental Affairs confirmation hearing on Capitol Hill in Washington, DC, on March 18, 2026. The US Senate on March 23 confirmed Markwayne Mullin as the new chief of the Department of Homeland Security (DHS), the agency reeling from a partial government shutdown as it works to enforce President Donald Trump's immigration crackdown. (Photo by Oliver Contreras / AFP via Getty Images)