Republican senators celebrated President Trump's decision to replace Homeland Security Secretary Kristi Noem with Sen. Markwayne Mullin (R-Okla.). Why it matters: Congressional Republicans — along with the White House — are eager to turn the page on a department that's dragging down the party's image on immigration , the very issue it rode to victory in 2024. Trump wasn't a "happy cowboy" about Noem and her $200 million media campaign , Sen John Kennedy (R-La.) said. Many Senate Republicans were just as angry as the president and were already preparing Thursday afternoon for a fast confirmation process on Mullin. Mullin is "pretty well vetted around here, so hopefully we can get the process going because I think that's a position that's going to need to be filled quickly," Senate Majority Leader John Thune (R-S.D.) said. State of play: Democrats, while declaring good riddance to Noem, insisted that a change at the top would not unlock funding for DHS, which has been shut down since Feb. 14. "No one person can straighten this up until the president changes the whole agency," said Senate Minority Leader Chuck Schumer (D-N.Y.). "This is not an issue of personnel. This is an issue of policy." "I'm not going to vote for $1 more for that agency as long as they are body-slamming American citizens, barging into American homes without warrants or murdering Americans," Sen. Cory Booker (D-N.J.) said. Still, Booker acknowledged that Mullin's confirmation is likely a foregone conclusion. "If it's a 50-vote threshold, I would imagine he will be confirmed," Booker told Axios. Cabinet nominations require only a simple majority. The intrigue: There's serious beef between Mullen and Sen. Ran Paul (R-Ky.), the chair of the Committee on Homeland Security & Governmental Affairs, which will handle Mullin's nomination. "Rand Paul's a freaking snake," Mullin told a group at home in Tulsa last month. "And I understand completely why his neighbor did what he did," he said, apparently referring to an assault on Paul that left him with five fractured ribs . "And I told him that to his face," Mullin said . Zoom in: Trump's Truth Social announcement that he was replacing Noem was read aloud by Sen. Eric Schmitt (R-Mo.), who was hosting a lunch for colleagues off the Senate floor. "Jim Banks was flagging me down. He's like, 'Look at your phone. Look at your phone,'" Schmitt said. "So I saw it and just announced it to the group." "Markwayne will do a great job. He's strong on the border, and that's what we need," Schmitt added. Zoom out: Trump had been sounding out GOP senators in recent days about naming Mullin and made clear his anger at Noem for spending more than $200 million on an advertising campaign. "The president asked me what I thought about him, and I told him that I was very fond of Markwayne. I think he's smart," Kennedy said. In a contentious Tuesday hearing, Kennedy grilled Noem over a $200 million ad campaign that she said the president had authorized. Sen Thom Tillis (R-N.C.) berated her for her overall performance and brought up an anecdote in her memoir where she bragged about killing a dog . "Senator Markwayne Mullin is a great guy and a great choice to lead DHS," Tillis said Thursday on X . "Another big positive: He likes dogs."