Article II Section 2

The President shall be Commander in Chief of the Army and Navy of the United
States, and of the Militia of the several States, when called into the actual
Service of the United States; he may require the Opinion, in writing, of the
principal Officer in each of the executive Departments, upon any subject
relating to the Duties of their respective Offices, and he shall have Power
to Grant Reprieves and Pardons for Offenses against the United States, except
in Cases of Impeachment. 

He shall have Power, by and with the Advice and Consent of the Senate, to
make Treaties, provided two thirds of the Senators present concur; and he
shall nominate, and by and with the Advice and Consent of the Senate, shall
appoint Ambassadors, other public Ministers and Consuls, Judges of the
supreme Court, and all other Officers of the United States, whose
Appointments are not herein otherwise provided for, and which shall be
established by Law: but the Congress may by Law vest the Appointment of such
inferior Officers, as they think proper, in the President alone, in the
Courts of Law, or in the Heads of Departments. 

The President shall have Power to fill up all Vacancies that may happen
during the Recess of the Senate, by granting Commissions which shall expire
at the End of their next Session.