From mass deportations to White House chief, how Stephen Miller became Trump's key pick

President Donald Trump has appointed Stephen Miller as the White House Chief of Staff, placing the architect of his hardline immigration policies at the forefront of his administration as he heads into a likely clash with Democrats following the Republican Party's midterm election losses. Miller, 41, is set to begin his new role on Monday, replacing Susie Wiles who has served in the position throughout Trump's second term.

The appointment comes as Democrats prepare to launch extensive investigations into the administration, including its immigration enforcement policies. With control of Congress shifting to Democrats, Miller is expected to play a crucial role in defending Trump's agenda and managing the administration's response to congressional scrutiny.