White House Chief of Staff Reince Priebus told me last weekend that the arrival of Anthony Scaramucci would mean "a fresh start" for the West Wing. This wasn't what he had in mind.

Landing in the rain at Andrews Air Force Base, Trump tweeted that his new chief of staff would be his Homeland Security secretary, retired Marine Gen. John Kelly, age 67: "He is a Great American ... and a Great Leader. ... He has been a true star of my Administration."

Trump tweeted that his new chief of staff would be his Homeland Security secretary, retired Marine Gen. John Kelly, age 67: "He is a Great American ... and a Great Leader. ... He has been a true star of my Administration." Trump loves generals — his Cabinet is unusually heavy with them.

— his Cabinet is unusually heavy with them. One West Wing confidant emails: "Trump is casting his show. Generals are all-purpose actors in a supporting role."

As an afterthought, Trump sent a separate tweet thanking Reince Priebus for his service. Priebus, whose 190-day tenure was the shortest in history for a non-interim White House chief of staff, had become so weak internally that one aide called him "the Chief of No Staff":

From the beginning, Trump had derisively referred to him as "Reincey" or "my genius Reince."

Trump had derisively referred to him as "Reincey" or "my genius Reince." Axios' Jonathan Swan , in his instant analysis: "[T]he Oval Office resembled a 'rolling craps game' ... Multiple senior officials have told me he 'gums up' the system and by the end was almost solely in survival mode."

, in his instant analysis: "[T]he Oval Office resembled a 'rolling craps game' ... Multiple senior officials have told me he 'gums up' the system and by the end was almost solely in survival mode." "[N]ot a single senior White House official came out to defend him as ... Scaramucci pummeled him on TV and accused him of being the building's chief leaker."

A top aide told me Kelly will "professionalize" the West Wing. My scouting report:

Kelly has a reputation for efficient management of complex organizations, and is a no-nonsense guy who can make the trains run on time.

for efficient management of complex organizations, and is a no-nonsense guy who can make the trains run on time. He looks the part, always big with President Trump.

always big with President Trump. Kelly won't tolerate a disruptive environment, and will try to normalize the reporting lines that usually would go to the chief of staff but have been going directly to the President.

a disruptive environment, and will try to normalize the reporting lines that usually would go to the chief of staff but have been going directly to the President. Swan was told: "He was given full authority. Everyone goes through him."

"He was given full authority. Everyone goes through him." One big challenge: Trump doesn't like to be told what to do, even by his generals.

Trump doesn't like to be told what to do, even by his generals. Amazing quote from an outside adviser to the West Wing: "Kelly, being a mature general, may finally be able to get Donald to pivot into a presidential dynamic."

Besides reining in Trump, Kelly's other big challenge will be corralling a staff that has run wild.

One top official told me: "No one says 'Yes, sir' in this White House. We say: 'F--- you.'"

P.S. ABC's Jon Karl reported on "World News Tonight" that one of the candidates to replace Kelly at Homeland Security is ... Attorney General Jeff Sessions!