“Give me liberty…”
The presidential oath of office is required by Article 2, Section 1 of the Constitution, which deals with the executive branch and outlines how the president is elected. In part, it reads:
Before he enter on the Execution of his Office, he shall take the following Oath or Affirmation:–
“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.”