Grounding flights
Grounding of flights was a tactical judgment that I know was supported by the entire government and probably all of us as well (although I thought it should've rebounded quicker). It wasn't the executive branch claiming some right of ascension above all other branches of government. The FAA is clearly under the control of the executive branch. No changes to the chain of command had to be made to do this step.
So that's all you've got? I notice you failed to answer the question as well.
Art