Mullin to DHS: who might replace him in the Senate, plus other repercussions

With the news that President Donald Trump is tapping U.S. Senator Markwayne Mullin (R-OK) to be the new Department of Homeland Security secretary, the 2026 Oklahoma election cycle has been thrown into another round of chaos.

Assuming Mullin's almost-certain confirmation, that will necessitate an interim appointment by Gov. Kevin Stitt to fill out the remainder of Mullin's Senate term (through January 2027). By Oklahoma statute, a temporary appointee pledges to not run for the full-term position. Thus, the appointee will be a lame-duck placeholder, while a fresh slate of candidates will compete for the full 6-year Senate term in the November 2026 election.

With the near-total collapse of the Democratic Party in Oklahoma, the next United States Senator will be decided in the June 16th Republican Party primary (and August 25th runoff). Expect a crowded and competitive field, running in a short election cycle.

Already, names are being bandied about as to who may run for the seat. Mullin's resignation to take the DHS position will trigger cascading effects on downballot races in Oklahoma.

Potential picks for U.S. Senate appointment 

Gov. Kevin Stitt will have the opportunity to select a temporary appointee to fill out the last months of Sen. Mullin's term. Per Oklahoma Statute Title 51, Section 10, he has 30 days to pick the successor, who must be from the same party as the vacating official (Republican, in this case). Furthermor, "[A] person who is a prospective appointee shall submit to the Secretary of State an oath affirming that the person will not file as a candidate for the office when it next appears on the ballot."

In a scoop by formerly Oklahoma-based reporter Reese Gorman, 80 year-old oil tycoon Harold Hamm has reached out to both Gov. Stitt and the White House to ask for the job. Gov. Stitt... for the love of all things good, please do not go this route. 

Others being mentioned include former Attorney General John O'Connor, former Trump official and 2022 Senate candidate Alex Gray, Donelle Harder (a longtime Stitt associate), businessman Dustin Hilliary, and Lieutenant Governor Matt Pinnell. O'Connor would make the most sense to me as someone with something of a proven political record as a conservative, friendly to Stitt, and unlikely to use this brief service as a springboard to future political roles.

Potential U.S. Senate candidates for Mullin's seat

1st District U.S. Rep. Kevin Hern (R-Tulsa) is almost certain to run for the Senate. He is already getting endorsements from fellow House colleagues (none from Oklahoma) and Senate Republicans such as Ron Johnson (R-WI). 5th District U.S. Rep. Stephanie Bice has said she is considering a run for Senate (I got a poll call this morning mentioning her as a candidate). Gov. Kevin Stitt could be a possibility as well. State Sen. Dusty Deevers has responded to social media encouragement for the seat, indicating that he is running for re-election but will pray about it; I would greatly discourage him from attempting a U.S. Senate run, as we need every strong conservative that we can get in the legislature.

Might a current candidate for one of the statewide positions switch races - T.W. Shannon (running for Lt. Gov. currently, ran for Senate in 2022), Chip Keating (running for Governor)? Gubernatorial candidate Mike Mazzei has shot down rumors that he might run for Senate.

What about former State Superintendent Ryan Walters? I could see him jumping into the Senate race or another downballot position that opens up. 

Other repercussions in Oklahoma races

If Hern and/or Bice run, their congressional seats would open up. Expect several current or former members of the legislature or other offices to run for those seats. Might we see a 1st Congressional District run for Lt. Gov. Matt Pinnell, another try by former State Sen. Nathan Dahm, former Tulsa mayor G.T. Bynum? Word on the street is that Jed Cochran (a former staffer for U.S. Sens. Coburn and Inhofe and Mayor Bynum) is interested in CD1. What about current legislators, like Sen. Dave Rader?

In CD5, perhaps term-limited State Sen. Shane Jett will give it another try (he ran in 2010), or maybe OKC Mayor David Holt (from the moderate/liberal GOP wing). This is the best chance that Democrats have at winning, having briefly taken the seat in the 2018 election. Perhaps other legislators like Sen. Adam Pugh would take a look at the seat.

Expect some relatively-unknown outsider candidates (businessmen, activists, etc.) to also play major roles in these elections.

Short time frame to decide

Things will happen quickly as the filing period for candidacy will be April 1st to 3rd. Expect a lot of things to happen in short order.

What are your thoughts? Drop a comment, or engage on the MuskogeePolitico Facebook or Twitter/X pages.