The Senate advanced Oklahoma GOP Sen. Markwayne Mullin's nomination for the Department of Homeland Security secretary, setting up a final vote on Monday to confirm him.

The upper chamber voted 54-37 on Sunday to advance Mullin's nomination, setting up a final vote on Monday, POLITICO reported. Democratic Sens. John Fetterman of Pennsylvania and Martin Heinrich of New Mexico crossed party lines and voted to advance Mullin's nomination.

Heinrich said that he considers Mullin a friend and that they have a “very honest and constructive working relationship.”

“I have also seen first-hand that Markwayne is not someone who can simply be bullied into changing his views, and I look forward to having a Secretary who doesn’t take their orders from Stephen Miller,” Heinrich added.

Mullin, who became a senator in 2023 after serving in the House, was tapped by President Trump to succeed Kristi Noem as DHS secretary after a wave of public criticism, including from some Republican lawmakers.

In the Homeland Security and Governmental Affairs Committee last week, Mullin suggested that he would be making some policy changes in DHS.

“My goal at six months is that we’re not in the lead story every single day,” Mullin said.

He will take over DHS while it’s in the midst of a weeks-long shutdown after congressional Democrats refused to pass a bill to fund it unless immigration enforcement changes are made, following federal agents killing two people in Minneapolis.