According to Dana Nelson, a professor of American studies at Vanderbilt University, "the theory of the unitary executive, first proposed under President Reagan, has been expanded since then by every president."^[12] In fact, the unitary executive was a matter of controversy long before the Reagan administration. For example, in the 1926 case of Myers v. United States, the United States Supreme Court decided that the President has the exclusive power to remove executive branch officials, and does not need the approval of the Senate or any other legislative body. The Court also wrote:

The ordinary duties of officers prescribed by statute come under the general administrative control of the President by virtue of the general grant to him of the executive power, and he may properly supervise and guide their construction of the statutes under which they act in order to secure that unitary and uniform execution of the laws which article 2 of the Constitution evidently contemplated in vesting general executive power in the President alone.^[13]

Subsequent cases such as Humphrey's Executor v. United States (Presidential removal of certain kinds of officers), United States v. Nixon (executive privilege), and Bowsher v. Synar (control of executive functions) have flexed the doctrine's reach back and forth. Justice Scalia in his solitary dissent inMorrison v. Olson argued for an unlimited presidential removal power of all persons exercising executive branch powers, which he argued included theindependent counsel; the court disagreed, but later moved closer to Scalia's position in Edmond v. United States.^[14]