Mulvaney — who is technically on leave from his first administration job as budget director — spends considerably less time with Trump than his two previous chiefs of staff, Reince Priebus and John F. Kelly. And the president has sometimes kept him out of the loop when making contentious foreign policy decisions, advisers say. At a recent donor retreat in Chicago, Mulvaney told attendees that he does not seek to control the president’s tweeting, time or family, one attendee said. Priebus and Kelly had clashed with the president over his Twitter statements and the influence of his eldest daughter and her husband, who are senior advisers.

Instead, Mulvaney has focused much of his energy on creating a new White House power center revolving around the long-dormant Domestic Policy Council and encompassing broad swaths of the administration. One White House official described Mulvaney as “building an empire for the right wing.”

He has helped install more than a dozen ideologically aligned advisers in the West Wing since his December hiring. Cabinet members are pressed weekly on what regulations they can strip from the books and have been told their performance will be judged on how many they remove. Policy and spending decisions are now made by the White House and dictated to Cabinet agencies, instead of vice versa. When Mulvaney cannot be in the Oval Office for a policy meeting, one of his allies is usually there.