President Donald Trump’s plan to nominate U.S. Sen. Markwayne Mullin of Oklahoma as Homeland Security secretary will leave an unexpected Senate vacancy in deep-red Oklahoma.

Under a new Oklahoma law, Gov. Kevin Stitt will get to pick Mullin’s replacement if he does indeed leave his Senate seat. Stitt said in a statement Thursday he will look to appoint “a strong, small government conservative voice to support President Trump.”

Read the full story at AP News.