Senate Majority Leader John Thune said he is confident Sen. Markwayne Mullin will be confirmed as the next secretary of Homeland Security despite a contentious exchange with fellow GOP Sen. Rand Paul at a hearing Wednesday.

Paul, the chair of the Homeland Security and Governmental Affairs Committee, sharply questioned the Oklahoma senator about past remarks that he “understood” why Paul suffered a heinous assault from a neighbor in 2017. Mullin refused to apologize for the remark.

“Those two obviously have some history, and it’s, you know, personal stuff,” Thune said. “They’ve got to work through it. I mean, in the end, this is about the job, and it’s about making sure that we got the right person there. I think Markwayne is the right person for the job.”

Asked if he was still confident Mullin can be confirmed, Thune said, “Yeah.”

Paul has scheduled a committee vote on Mullin for Thursday. While Paul’s vote is in serious doubt, Mullin could win over Democratic Sen. John Fetterman of Pennsylvania, who has expressed support for Mullin previously and said Wednesday he would approach the nomination “with an open mind.”

“I haven’t been rocked by some mic-dropping kind of moments,” Fetterman told reporters after the hearing.

Sen. Markwayne Mullin said he regretted calling Alex Pretti “deranged” but stopped short of offering a direct apology to Pretti’s family.

“I shouldn’t have said that,” the Oklahoma Republican said during his confirmation hearing Wednesday to serve as the next Homeland Security secretary. He was referring to his past comments regarding the U.S. citizen killed by federal immigration enforcement agents in Minnesota back in January, who some conservatives in the immediate aftermath labeled a “domestic terrorist.”

It was a stronger concession than Mullin gave just moments earlier, when he refused to apologize for calling Sen. Rand Paul (R-Ky.), the chair of the Homeland Security and Government Affairs Committee, a “snake.” Still, when pressed by the committee’s top Democrat, Sen. Gary Peters of Michigan, Mullin would not commit to apologizing to Pretti’s family until the conclusion of an investigation into the incident.

“If I’m proven wrong, then I will,” Mullin said.

Regarding Renee Good, another U.S. citizen killed by immigration enforcement officers in Minnesota earlier this year, Mullin refused to retract comments he made at the time of Good’s death, specifically that agents were justified in killing her. He told BLN in January that agents “had the right to defend themselves.”

He said he would wait for the findings of the investigation into Good’s killing to comment further; Sen. Richard Blumenthal (D-Conn.) countered that the Trump administration is currently blocking state and local inquiries.

A committee vote on Sen. Markwayne Mullin’s confirmation as Homeland Security secretary remains on track for Thursday despite a fiery sparring session Wednesday between the Oklahoma Republican and Sen. Rand Paul of Kentucky, the chair of the panel that must approve his nomination.

A spokesperson for Paul said after the tense exchange — during which Mullin refused to apologize for comments saying he “understood” why Paul was violently assaulted in 2017 — that the committee vote “is on for tomorrow.”

As chair of the Homeland Security and Governmental Affairs Committee, Paul has wide latitude to schedule action on Mullin’s nomination.