I don't think the "souring" is it.
This is politico's take, of course, not the administration's, but it's the view of the beltway world in which three of the dumbest fucking Republicans in punditry are a Dem president's "staunchest media allies."
Oh no what will they do if they've lost Josh "My Dad, Robert, is also an asshole" Barro.
Politics is 100% vibes for Rubin and Brooks, and Barro is an incoherent glibertarian.