President Trump's appointment of Mullin to lead the U.S. Department of Homeland Security creates a vacancy in the U.S. Senate during an election year.
It's a situation Republican lawmakers now in leadership planned for six years ago.
Senate Pro Temp Lonnie Paxton, R-Tuttle, proposed and passed Senate Bill 959 in 2021, with the help of House Speaker Kyle Hilbert, R-Bristow. The measure mandates that the governor fill Oklahoma's U.S. Senate vacancy within 30 days and serve until the next regular election.
Paxton says this is among the scenarios he envisioned and wanted to mitigate.
"The way this was unfolding is…Senator Mullin's seat is up this year anyway," Paxton said. "The governor has the ability to appoint somebody. And then people will file for that office in April just like everybody else will."
But there is one key stipulation to accepting a gubernatorial appointment to the Senate. Whoever it is has to sign a form stating they won't seek re-election to the same seat immediately after their term. And while it's not enforceable by law, Paxton said, he hopes it will serve as an accountability measure.
"It's really not enforceable from the standpoint of kicking somebody off the ballot," Paxton said. "It's enforceable to make him sign it and put it out there. But when it comes time, if somebody was running and they were challenged…their opponents can certainly hold it up and say 'the first thing this person did was lie to everybody when they said they wouldn't run for that office.'"
It's the first time the provision is being tested, as Oklahoma's candidate filing period starts days after Mullin is set to take control of the Homeland Security department, from April 1 to April 3.
Hilbert said he remains open to making quick tweaks to the 2021 legislation if needed, but stopped short before saying what those might be, as he hadn't yet talked to Paxton since news of Mullin's appointment broke just after lunchtime Thursday.
Legislative leadership is supportive of Mullin
Overall, Republicans like Paxton and Hilbert said they have a positive relationship with Mullin and support the junior senator's appointment to a more senior position within Trump's Cabinet.
"I totally understand why President Trump would want to appoint Senator Mullin to that position," Hilbert said. "I think he's somebody you know, could step into a role that's a very heated place for our country right now and would be a great asset to the United States."
Democratic leaders expressed more hope than confidence that Mullin would do a better job than his predecessor, Kristi Noem, whose time as Secretary of Homeland Security was mired in controversy — most recently over a $220 million ad campaign she was heavily featured in.
"Secretary Noem…the way that her agency while she was in charge…the way that they were treating human beings was, I mean, just a disgrace and a disservice to this country," House Minority Leader Cyndi Munson said.
The Department of Homeland Security oversees immigration enforcement, among several other policy areas relating to the security of the nation's interior.
She said she hopes Mullin will be more in touch with Americans on that front.
"I hope he comes back to his home state and talks to people who have been impacted by ICE and the various challenges that communities have been facing, and tries to do better," Munson said. "I worry that that may not be the case."
