Historically, this core unity has always tolerated some degree of fractiousness within the executive branch. One extreme example from early in the republic’s history is that of Thomas Jefferson, who funded and ran an opposition newspaper while serving in George Washington’s cabinet. Lower executive-branch officials often have statutory responsibilities of their own delegated to them by Congress, and civil servants are not appointed and removed at will by the president. The unity fiction became a bit more strained as the executive developed into an immense series of interlocking bureaucracies, including the supposedly independent federal regulatory agencies, over the course of the 20th century. Presidential lack of control over the State Department has long been a source of some consternation. And, of course, regardless of the president’s status as commander in chief, the military is a world of its own. The question of unity has always been one of degree; it is not absolute. That said, the idea of unity remains true in important respects.

When Trump took the oath of office, he assumed certain powers, all of which Article II, Section 2 of the Constitution vested personally in him: He became commander in chief of the military; he became responsible for appointing and supervising all heads of agencies and cabinet departments—including having the power to remove them from office; he was empowered to pardon criminals and those being prosecuted, to reprieve sentences, and to remit fines; he was empowered to make treaties with foreign governments, and thus to withdraw from them; he was given the power to appoint ambassadors and judges with the Senate’s advice and consent; he was given the power to veto legislation. All these powers came to Trump personally—not to his cabinet officials, not to his staff, not to Republican congressmen, but to him.

Alexander Hamilton’s “Federalist No. 70” is the essential starting point in a discussion of the executive branch. “Energy in the Executive,” wrote Hamilton, “is a leading character in the definition of good government. It is essential to the protection of the community against foreign attacks.” The reason? “A feeble Executive implies a feeble execution of the government. A feeble execution is but another phrase for a bad execution; and a government ill executed, whatever it may be in theory, must be, in practice, a bad government.” Translation: If you want government to do things, you have to have an executive capable of it. Designing the executive branch in this fashion was controversial, with many of the opponents of the Constitution arguing that the president’s broad powers too closely resembled the monarchical power the colonies had only recently shaken off.

The modern presidency has powers Hamilton surely never imagined. In particular, the war powers have migrated—to what degree is a matter of debate, but certainly to some degree—from the legislature to the presidency, bringing unity of action and decision making to the powers of war and peace to a degree the Founders certainly did not envision. Similarly, the rise of informal international agreements that are not subject to the demands of the treaty power has concentrated a great deal of foreign-policy authority in the hands of the president. And the growth of the standing, institutional military transforms the commander in chief’s power in peacetime into something much bigger than it was in Hamilton’s time. What’s more, in many areas, Congress has delegated huge swaths of authority to the executive branch.

The basic structure, however, remains more or less as it was in Hamilton’s day, albeit much larger and with important exceptions that limit presidential control over independent agencies and lower-level officials across the government. The executive branch remains, broadly speaking, a vertically integrated organization with a single person at its apex.