Per the Constitution, all power of the Executive resides in a single person, the President.
He is not insulated, as it is his delegation of that power that is enforced.
We got plenty of folks, that haven't a clue what "delegation"
really means.
You CAN delegate Authority, but you can NOT delegate Responsibility.
I am sure Truman did NOT push the buttons to release two nukes over Japan. He had delegated responsibility to his chain of command to do so.
But Truman himself, still had ultimate Responsibility.
These days politicians often claim no involvement, even though their subordinate did something wrong.
They disavow responsibility.