NYTimes broke the story. All they really have is this:
The person briefed on the change said that the campaign is looking toward bringing the party together, including hiring new staff members and adjusting to the campaign’s needs for the race against Mrs. Clinton. And there had been a desire for many weeks to make changes ahead of the convention, July 18-21 in Cleveland, particularly since it became clear that Mr. Trump would be the nominee.
And now that it appears that Trump's campaign is a total dumpster fire of fail with an utterly out of control candidate who can't etch-a-sketch worth sh*t, it's important that someone ELSE take the blame for the very bad past few weeks this candidate has brought upon himself.
Last week Trump told the RNC to "be quiet or at least let me do this by myself." Will he have ANY staffers left by November?
— Michelle Fields (@MichelleFields) June 20, 2016