John Kelly, a retired four-star Marine general, has been worn in as the new White House Chief of Staff

John Kelly who began his career in the Marine Corps has served a total of five decades in the armed forces

James Baker, who held the position under two presidents, offered some advice: “You can focus on the ‘chief,’ or you can focus on the ‘of staff.’ Those who have focused on the ‘of staff’ have done pretty well.”

Some Republicans have cheered Mr. Kelly’s new role — and the ouster of his predecessor, Reince Priebus — even as they worry about a series of setbacks to President Trump’s agenda.

Analysts believe that not much might change with the new assignment given that Trump has surrounded himself with men like his son-in-law Jared Krushner.

In six months since assumption of office, Trump has fired a national security adviser, an F.B.I. director and a holdover acting attorney general, while his White House press secretary, communications director, deputy chief of staff, deputy national security adviser and legal team spokesman have all left.

Who will be fired next and who will be hired next?