Constitutional Expressed Powers
The Const says very little about pres power. The discussion of the presidency begins with these general words: "The executive power shall be vested in a president of the US." It lists a few powers of the pres. The framers check those powers they believed to be most dangerous while protecting the general spheres of authority from encroachment (i.e. veto power). Some are: serves as commander in chief, makes treaties, nominates ambassadors, conferring diplomatic recognition on other gov'ts, present info on state of the union to Cong, "take care that laws be faithfully executed," nominate federal judges, etc.