WASHINGTON, DC - MARCH 24: Newly sworn-in Sen. Alan Armstrong (R-OK) (L), accompanied by his wife Shelly (C), pose for a photograph following a ceremonial swearing in ceremony with Senate President Pro Tempore Charles Grassley (R-IA) in the Old Senate Chamber at the U.S. Capitol Building on March 24, 2026 in Washington, DC. Armstrong, a longtime petroleum executive, was sworn in as an interim Senator for Oklahoma to replace Markwayne Mullin, who was tapped to replace Kristi Noem as the new U.S. Secretary of Homeland Security. (Photo by Andrew Harnik/Getty Images)