The Constitution has this to say about the presidential oath of office:
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.”

The Constitution has this to say about the role of the courts:
The Judicial Power of the United States, shall be vested in one supreme Court, and in such inferior Courts as the Congress may from time to time ordain and establish. The Judges, both of the supreme and inferior Courts, shall hold their Offices during good Behavior … The Judicial Power shall extend to all Cases, in Law and Equity, arising under this Constitution [or] the Laws of the United States …
