Stephen Miller serves as Trump’s deputy chief of staff and homeland security adviser and is the driving force behind Trump’s immigration crackdown|Gage Skidmore|CC BY-SA 2.0

President Donald Trump announced plans yesterday to replace chief of staff Susie Wiles with longtime adviser Stephen Miller, following his party’s midterm losses.

Miller serves as Trump’s deputy chief of staff and homeland security adviser and is the driving force behind Trump’s immigration crackdown.

Wiles will take on a role in Trump’s political operation.