Stephen Miller's rise from immigration architect to White House chief of staff

President Donald Trump has appointed longtime adviser Stephen Miller as White House chief of staff, placing a key architect of his hardline immigration agenda at the center of his administration ahead of expected clashes with Democrats after Republican midterm losses. Miller, 41, will replace Susie Wiles on Monday, with Trump calling him one of his "most trusted" advisers. The appointment comes as Democrats prepare sweeping investigations into immigration enforcement, and Miller is expected to defend the president's agenda and manage responses to congressional scrutiny. Miller has shaped Trump's immigration policies across both terms, including the travel ban, family separations, and mass deportation efforts. His elevation signals Trump's commitment to his America First agenda despite electoral setbacks and growing political backlash over enforcement tactics.