What is the presidential oath of office?
The vice-president-elect is sworn in first and repeats the same oath of office, in use since 1884, as senators, representatives, and other federal employees:
"I do solemnly swear (or affirm) that I will support and defend the Constitution of the United States against all enemies, foreign and domestic; that I will bear true faith and allegiance to the same; that I take this obligation freely, without any mental reservation or purpose of evasion; and that I will well and faithfully discharge the duties of the office on which I am about to enter: So help me God."
Later, the president-elect recites the following oath in accordance with Article II, Section I of the U.S. Constitution:
"I do solemnly swear (or affirm) that I will faithfully execute the Office of President of the United States, and will to the best of my ability, preserve, protect and defend the Constitution of the United States."