US President Donald Trump on Friday appointed Stephen Miller, one of the most influential architects of his hardline immigration policy, as his new White House chief of staff, replacing Susie Wiles just days after the Republican Party suffered a major defeat in the midterm elections.Miller, 41, currently deputy chief of staff and homeland security adviser, will assume the position on Monday, November 9, Trump announced on his Truth Social platform.“I am pleased to announce that Mr. Stephen Miller, the current Deputy Chief of Staff of the Trump Administration, and one of my most trusted advisors, will become the Chief of Staff,” Trump wrote.Wiles, 69, the first woman to serve as White House chief of staff, will move to Trump’s political operation. The president praised her performance, describing her tenure as outstanding.Wiles confirmed her departure in a statement on X, saying that serving Trump in the White House had been “the honor of a lifetime”. She highlighted the administration’s record on border security, tax cuts and its economic policies.Miller has been one of Trump’s closest advisers for more than a decade, dating back to his first presidential campaign in 2016. He has played a central role in shaping the administration’s restrictive immigration policies, including its drive to carry out mass deportations during Trump’s second term.His promotion places one of the administration’s most outspoken advocates of tougher immigration enforcement at the centre of White House decision-making.The appointment also comes amid growing scrutiny of the administration’s immigration operations, particularly following the fatal shootings of two protesters by immigration agents in Minneapolis in January, which triggered widespread demonstrations and criticism of federal enforcement tactics.The personnel change follows a bruising midterm election for Republicans, with Democrats winning control of both chambers of Congress. The result represents a significant political setback for Trump and is likely to intensify scrutiny of his administration’s domestic agenda.Wiles had been widely regarded as an important organisational force within Trump’s inner circle, helping manage competing interests and maintain discipline in the White House. Her departure also follows weeks of speculation about possible personnel changes, although the administration had previously rejected reports that she was about to be replaced.By moving Wiles to his political operation and promoting Miller, Trump is reshaping his closest circle of advisers at a politically sensitive moment.