The President of the United States has a number of different roles, both formal and informal. But arguably the most important of these, certainly in terms of domestic policy, is that of chief executive. In very basic terms, the president is rather like the CEO of a company in that they set the agenda of his Administration and make all the major decisions concerning the implementation of that agenda.

Pressing the analogy with the CEO of a company a little further, we could say that the various departments of the federal government are rather like the many departments, such as finance and marketing, that make up a modern corporation. In both cases, though, it's the person at the top who seeks to marshal all the available resources to achieve specific policy goals.

In achieving their policy agenda, the president will want to have people around them that they can trust. In their role as chief executive, they have enormous powers of patronage and are responsible for the hiring and firing of large numbers of federal employees and officials.

Of course, the president, even in their powerful role as chief executive, doesn't have it all their own way. To get their legislative agenda enacted, they have to work with Congress to ensure that it becomes law. A good president is therefore someone who can work with numerous legislators, including their political opponents, to achieve their objectives.