Ah, where to begin. The abrupt departure of Gary D. Cohn, one of Mr. Trump’s top economic advisers as director of the National Economic Council was the most recent and high-profile departure but was hardly the only one. Just in the past two weeks, there’s been Hope Hicks, his communications director, hitting the road as well as Rob Porter, the staff secretary who left over abuse allegations. And don’t forget the fall of aide Omarosa Manigault-Newman, Health Secretary Tom Price, the inexplicable Sebastian Gorka, who supposedly had some involvement in foreign policy, or real-life Sith Lord Steve Bannon. Not since Omarosa was a regular on “The Apprentice,” where each week a contestant was dramatically ejected from the boardroom, has a Trump enterprise produced such a rush to the exits.