Oklahoma Gov. Kevin Stitt is considering five candidates to replace Sen. Markwayne Mullin (R-OK), who President Trump tapped to become the next Secretary of Homeland Security. BREAKING: President Trump Names DHS Secretary Replacement Stitt must appoint a replacement within 30 days after Mullin formally vacates his seat. News9 shared the list of candidates: Nathan Dahm — Served as chair of the Oklahoma Republican Party from 2023 to 2025. Previously served as an Oklahoma state senator from 2012 to 2024. David Ostrowe — Currently serves as chief operating officer in the governor’s office. John O’Connor — Served as Oklahoma attorney general from 2021 to 2023. Dustin Hilliary — Currently serves as a senior advisor to Stitt. Hilliary is co-CEO of Hilliary Communications. Harold Hamm — An oil and gas executive and billionaire best known as the founder of Continental Resources and a noteworthy figure in the U.S. shale oil boom. A second source familiar with the situation tells News 9 that Hilliary was contacted by the governor’s office regarding the Senate appointment.