Washington — President Trump moved Friday to install longtime aide Stephen Miller as his White House chief of staff, replacing Susie Wiles in the most significant shakeup of his team since Republicans’ losses in the midterm elections.

“I wanted to make a change,” the president told reporters shortly after announcing his decision on Truth Social. “I think Susie’s done a very good job, great job, but I just wanted to make a — Stephen’s been great. And we’ve got to make moves. Sometimes, sometimes in life, you have to make moves.”

In his Truth Social post, the president called Miller “one of my most trusted advisors” and said he would begin his new role on Monday. “Susie Wiles, who has done an outstanding job, will be moving over to the Trump Political Operation,” he wrote. “I want to thank her for her service as Chief of Staff — She has done a great job!”

Wiles submitted her resignation to the president on Thursday night, a U.S. official and a senior White House adviser told WTX US News. Her resignation was tied to Republicans’ midterm defeats, according to three sources familiar with the matter. It was unclear if her deputies would remain at the White House.

Wiles had planned to stay on as chief through Congress’ lame-duck session and exit after that, likely at the end of this year or early next year, according to sources familiar with her thinking. The president accelerated her departure.

Miller has been one of Mr. Trump’s closest and most loyal aides for years. He has a broad portfolio in the White House, including as the architect of the president’s immigration enforcement and deportation program. The president told reporters Miller is “very good politically” and is a “great manager.” 

Wiles ran Mr. Trump’s 2024 presidential campaign and has been his chief of staff since his first day back in the White House.

“Today is my last day as White House Chief of Staff,” Wiles posted on X. “Serving President Trump in the White House has been the honor of a lifetime. I’m so proud to have been a part of what we’ve accomplished together from securing our border and cutting taxes to strengthening our economy and putting America First. More than anything, I’m grateful for the extraordinary people I’ve had the privilege of working alongside. While my role may be changing, my commitment to the president and the mission never will.”

Miller thanked “the incomparable Susie Wiles,” and said the “mission is more clear than ever: Fight with all of our soul to support our President and defend this magnificent Republic.”

Mr. Trump’s decision to install Miller as chief of staff represents a doubling down on his approach to governing, despite voters’ widespread rejection of his and congressional Republicans’ agenda on Tuesday. 

Miller is loathed by Democrats on Capitol Hill who see him as the driving force behind some of the president’s most hardline policies. The president has said in recent days that he thinks he can work with the incoming Democratic leadership, but Miller’s promotion could lay the groundwork for a much more confrontational relationship.

Indeed, top Democrats quickly denounced the move and vowed to ramp up the pressure on Miller once they take control of Congress in January.

“Donald Trump learned nothing from his historic defeat,” Senate Democratic leader Chuck Schumer said on X. “Stephen Miller is the architect of the most barbaric, inhumane policies of this administration. Trump couldn’t have made a worse choice. Our Democratic majorities will fight him every step of the way.”

House Democratic leader Hakeem Jeffries, likely the next speaker, called Miller “a dangerous xenophobe and reckless extremist who has American blood on his hands.” He said “his presence in government should be eradicated like a malignant tumor.”

Rep. Robert Garcia, who is in line to become chairman of the House Oversight Committee, said Miller “should lawyer up.”

“Oversight Democrats will continue to investigate Miller for his misconduct, and we will fight against his hateful policies in Congress and the courts,” Garcia said in a statement.