Former member of Congress
Markwayne Mullin
Republican · Former U.S. Senator from Oklahoma · 2023–2026
What happened
Markwayne Mullin left the U.S. Senate in February 2026. Left the Senate to become U.S. Secretary of Homeland Security.
No longer serving, so this page is a record rather than a live countdown. Source, checked September 18, 2026.
Who holds the seat now
Alan Armstrong (Republican) now holds this Oklahoma Senate seat.