Priebus resigned his position as White House Chief of Staff last Thursday, July 27th, after a rocky, 6-month tenure (the shortest in history). His resignation was the result of in-fighting among the President's senior staff, most notably accusations of leaking and disloyalty from newly appointed Communications Director Anthony Scaramucci. The President was reportedly upset that Priebus didn't "fight back" against Scaramucci's claims.
Scaramucci, days before Priebus's resignation, called a New Yorker reporter and accused him of being a leaker, a “paranoid schizophrenic, [and] a paranoiac.” During the same interview, Scaramucci also said of the Donald Trumps Chief Strategist:
I'm not Steve Bannon, I'm not trying to suck my own c***.
Even on Friday, after Priebus issued a statement that he would be leaving the White House, he refused to respond to Scaramucci. He told CNN’s Wolf Blitzer he wasn’t “going to get into the mud on those kind of things.”
Priebus and Scaramucci were in fairly open conflict since the Director of Communication's first day on the job. Scaramucci reportedly held a grudge over the fact that Priebus blocked him from getting a job within the administration for the first 6 months of Trump's presidency. The White House, meanwhile, did very little to quell rumors of in-fighting, or stop the conflict. Sarah Huckabee Sanders stated at a press conference that Trump "liked the competition" among staffers.
Now, according to a report from The Wall Street Journal, Trump was "dismissive" of the fact that Priebus didn't stand up for himself. He's hired former General John Kelly, a relatively non-political military figure, as the new White House Chief of Staff. While Republicans on Capitol Hill are hoping Kelly can bring some discipline to a White House buried in controversies, it may seem that President Trump wants just the opposite.
H/T - Huffpost, The Wall Street Journal