Things have clearly deteriorated inside the White House as Trump's impeachment proceeds and following recent reports that Trump has been shopping for replacements for his chief of staff Mick Mulvaney.
The Washington Post reported last night that Trump wants to replace Mulvaney, but his staff are trying to talk him out of it because Mulvaney could be a witness against him.
Senior advisers have cautioned Trump that removing Mulvaney at such a sensitive time could be perilous, the people said — both because Mulvaney played an integral role in the decision to freeze the aid, and because of the disruption that would be caused by replacing one of Trump’s most senior aides. [...]
Mulvaney had direct talks with Trump about the president’s desire to withhold nearly $400 million in security aid to Ukraine, The Washington Post has reported.
Meanwhile, the New York Times reports that Mulvaney has been telling his friends and associates that he knows too much about Trump's corruption to be fired.
Mr. Mulvaney, who has been left with an “acting” title for more than 10 months and therefore insecure in his position, is said to see Mr. Cipollone as angling for his job as chief of staff. People close to Mr. Cipollone deny that and say he is not interested, although they acknowledged that there were previous discussions with Mr. Trump about such a shift. [...]
Despite his own tenuous job status, Mr. Mulvaney has privately told associates in recent days that there is no easy way for Mr. Trump to fire him in the midst of the impeachment fight, the implication being that he knows too much about the president’s pressure campaign to force Ukraine to provide incriminating information about Democrats.
In any administration, the president's chief of staff is ostensibly their number one guy -- the person who serves as a point of contact and direction between the Oval Office and the entire cabinet.
In Trump's regime, his chief of staff is a potential witness against him who knows too much about the corrupt practices of the regime to easily replace.
I have my doubts that Mulvaney would actually expose Trump if he's fired, but Mulvaney may believe that making Trump think he could will allow him to keep his job for a little bit longer.
I'm not sure why he still wants the job. There will be no shortage of opportunities in the payday loan industry for Mulvaney if he departs.