“The executive Power shall be vested in a President of the United States of America,” begins Article II of the Constitution. It’s pretty straightforward. The president is the boss of the executive branch. The executive branch is an extension of him. What power it has, he delegates it.

There is no fourth branch of government, so every federal official or employee outside of the court system and Congress works for the president. While civil service laws protect most low- and mid-level employees, the higher-level officials serve mostly at the pleasure of the person sitting in the Oval Office.