The thing about Mulvaney is that he has proven himself to be a can-do guy...and Whitaker looks like he has lots of potential, but he has yet to prove it at the highest levels.
And Chief of Staff is the highest level albeit a gritty, dirty, and thankless job.
If Trump can get Mulvaney to forget about this "acting" crap, the WH just made a huge jump into the future.
BTW, as an aside, I think Mulvaney is also negotiating. That's why he said he would serve only as "acting" COS.
I'll be he told Trump, I'll take the job but only on conditions.
And one of those conditions is he gets to have final say on Trump's twitter account.;-)
Are you basing that on anything — or purely speculating?
Because without any basis I imagine any negotiated terms are favorable to Trump, not Mulvaney.