@Phil No. Only if you define "executive power" to be what is assigned to the President. The Constitution defines a balance of roles and activities, and includes Congress in the structuring of offices under the executive. It plainly has a role in defining roles and hiring (contradicting your "ALL executive power"), when it chooses to. 1/

@Phil It's a shame that the obvious corollary with respect to an ability to structure a role in firing is not discussed in the text one way or the other. The Humphrey's court resolved the ambiguity correctly. /fin