"A coup is never constitutional. In fact, it is a direct attack to the Constitution.
What then must a sitting president do? The president's oath provides the answer plainly.
"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."
It is worth repeating that the solemn duty of the president is to defend the Constitution."