The Senate voted 54-37 on Sunday to invoke cloture on President Donald Trump's nomination of Oklahoma Sen. Markwayne Mullin to lead the Department of Homeland Security, clearing the last major procedural hurdle before a final confirmation vote expected as early as Monday night. The surprise was not the outcome but who helped deliver it: New Mexico Democrat Martin Heinrich, a third-term senator who crossed party lines to advance Mullin's candidacy and announced he would vote to confirm him.
Heinrich joined Pennsylvania Democrat John Fetterman, whose crossover vote has become almost routine in this Congress, to give the nomination a bipartisan stamp that most of their caucus refused to provide. The two Democrats sided with nearly every Republican in the chamber. Only one GOP senator broke the other way: Rand Paul of Kentucky, the Homeland Security Committee chairman, who has waged a vocal campaign against Mullin's temperament.
The vote sets up what should be a straightforward confirmation within days. And it hands the Trump administration a win on homeland security at a moment when Senate Democrats have spent weeks blocking DHS funding and slow-walking the president's border agenda.
Heinrich's vote was the one nobody saw coming. In a statement issued after the cloture vote, the New Mexico Democrat acknowledged as much:
"This is going to surprise some people, but I consider Markwayne Mullin a friend. We have a very honest and constructive working relationship."
He pointed to shared legislative work, including the Tribal Buffalo Management Act, which the two senators reintroduced together in December 2025, and the Legislative Branch Appropriations bill they crafted this year. Heinrich framed his decision in practical terms, not ideological ones. For five years, he said, he lacked any constructive relationship with the secretary of Homeland Security. New Mexico shares many miles of the U.S.-Mexico border, and the state is home to hundreds of TSA, Customs and Border Protection, and Border Patrol personnel.
"I want someone who recognizes the necessity of judicial warrants, as he has. I would like a Secretary who I can call and have a constructive conversation with about my state and the unique terrain that exists in the southwest and the proper mix of structure, technology and personnel necessary to effectively secure our border."
Heinrich also took a swipe at the White House, saying he looked forward to "a Secretary who doesn't take their orders from Stephen Miller," Trump's deputy chief of staff. That line read like a hedge, a signal to his own base that he was not surrendering to the administration, even as he handed it a vote.
But the bottom line was clear. Heinrich wants a working relationship with whoever runs DHS, and he believes Mullin will pick up the phone. Whether that calculation pays off is another question. What it tells us right now is that at least one border-state Democrat has decided obstruction is a dead end.
If Heinrich's vote surprised Washington, Fetterman's did not. The Pennsylvania senator already broke ranks at the committee level, casting the decisive vote in an 8-7 party-line split that sent Mullin's nomination to the full Senate floor. As a member of the Homeland Security Committee, Fetterman gave Republicans the margin they needed when it mattered most.
He had telegraphed his position weeks earlier. On March 5, the same day Trump announced the nomination, Fetterman posted on X: "I'm not sure how many fellow Democrats will vote to support our colleague [Mullin] as the next DHS Secretary, but I am AYE."
Breitbart reported that Fetterman tied his support to a working relationship with Mullin on national security, saying his vote was "rooted in a strong committed, constructive working relationship with Senator Mullin for our nation's security." He also called for DHS to reopen, a reference to the ongoing funding standoff that has left parts of the department in limbo.
Fetterman's willingness to buck his party on Trump nominees has become a pattern. The senator has publicly accused Democrats of being driven by "Trump Derangement Syndrome" rather than serious leadership. His votes on Mullin are the latest evidence that he means it.
The only Republican to oppose Mullin was Paul, who chairs the very committee that held the nominee's confirmation hearing. The Washington Examiner reported that Paul did not vote on the cloture motion Sunday, though he had voted against Mullin in the committee's Thursday tally.
Paul's objection centered on temperament. During opening remarks at Mullin's Wednesday hearing, the Kentucky senator called him "a man with anger issues" and questioned whether someone who "applauds violence against their political opponents" should lead an agency that has "struggled to accept limits to the proper use of force." Paul was referencing comments Mullin made in February, when the nominee said he understood why Paul's neighbor violently attacked him in 2017.
Mullin pushed back directly during the hearing. "I did not say I supported it," he said of the 2017 attack. "I said I understood it. There's a difference." He added: "I'm not apologizing for pointing out your character."
The exchange was sharp, but it did not move votes. Paul stood alone among Republicans, and his opposition was not enough to slow the nomination.
If confirmed, Mullin would succeed Kristi Noem as DHS secretary. Polling showed strong public support for Trump's decision to make a change at the department, and Mullin brings a different profile to the job. He is the only American Indian member of the Senate, an enrolled member of the Cherokee Nation, and the first Native American to serve in the upper chamber since the late Colorado Republican Ben Nighthorse Campbell retired in 2005.
His home state of Oklahoma and Heinrich's New Mexico both have American bison populations numbering in the thousands, a shared interest that led to their work on the Indian Buffalo Management Act. Mullin described the legislation in terms rooted in tribal heritage: "The buffalo is essential to our heritage and must be supported. I am proud to reintroduce this important legislation that will help Tribes reestablish buffalo herds on reservation lands."
That kind of cross-party legislative work is rare in today's Senate. It also helps explain why Heinrich was willing to spend political capital on a Trump nominee. Personal relationships still count for something, even in a chamber that mostly runs on partisan reflex.
The 54-37 cloture vote means Mullin's confirmation is all but certain. The GOP-controlled Senate has the numbers, and two Democratic defections only widen the margin. A final vote could come as early as Monday night.
The timing matters. DHS has been at the center of a funding standoff that has dragged on for weeks, with Democrats blocking full appropriations and attempting to fund only select pieces of the department. Installing a confirmed secretary with bipartisan support strengthens the administration's hand in that fight. It also signals that the Senate's Democratic wall against Trump's homeland security agenda has cracks, and they are growing.
Heinrich and Fetterman voted for different reasons. Heinrich wants a working partner on border issues. Fetterman seems to have decided that reflexive opposition to every Trump pick is bad politics and worse governance. Both reached the same conclusion: Mullin deserves the job.
When even Democrats from border states start voting to confirm Trump's DHS secretary, the party's obstruction strategy isn't just failing. It's becoming impossible to defend.
