Long a shunner of the spotlight, Dunn, who declined to comment for this article, would only sign on in April as an “interim” chief, with an end-of-the-year expiration date on her current tenure. But giving up nominal power in the White House allows Dunn to do the dirty work that ultimately assures her staying power inside the administration.

A source inside the White House, who was not authorized to speak about strategy meetings, said Dunn went out front against Fox first and foremost because it was her job, but also because it potentially gave the administration the opportunity to distance itself from the flap with the Roger Ailes-led news channel once she leaves the communications job.