Stephen Miller takes White House chief of staff job after GOP midterm losses

The man who pushed for Immigration and Customs Enforcement to make at least 3,000 arrests a day will run the White House starting Monday.

President Donald Trump named Stephen Miller his chief of staff Friday, replacing Susie Wiles after Republicans lost control of both chambers of Congress in the midterm elections. Miller had been serving as deputy chief of staff and has been one of Trump's closest advisers since joining his 2016 campaign.

Why it matters: The White House chief of staff is the president's gatekeeper, agenda-setter and a central negotiator with Congress. Trump is putting that job in the hands of the adviser most associated with his hard-line immigration agenda just as Democrats prepare to control the House and Senate in January.

Trump called Miller one of his "most trusted advisors" and told reporters, "He gets it." Miller said he was "honored beyond words" and described his mission as supporting Trump and defending the country.

The record: Miller helped shape and defend the first Trump administration's restrictions on entry from several Muslim-majority countries, a later version of which the Supreme Court upheld. He was also a leading supporter of the 2018 zero-tolerance border policy that led to widespread family separations.

In Trump's second term, Miller pressed ICE to meet a minimum target of 3,000 arrests each day. CBS News reported that the enforcement expansion reached beyond people convicted of serious crimes, with arrests, detentions and deportations becoming a defining part of the administration's agenda.

The change at the top: Wiles submitted her resignation Thursday night and will move to Trump's political operation, according to Trump's announcement. CBS News, citing sources, reported that her departure was tied to the election losses. The BBC also reported that Trump had grown dissatisfied with Wiles and was frustrated by reports of consulting work among people in her orbit, so the full reason for the change is not settled.

Democratic House leader Hakeem Jeffries called Miller a "dangerous xenophobe and reckless extremist," while Democratic Congressman Robert Garcia said he plans to investigate Miller and his conduct when Democrats take over the House Oversight Committee.

The first consequential date is January, when Democratic majorities take control of Congress and begin deciding what oversight of the White House will look like.