Section 1 of Article II of the Constitution prescribes the oath each President is to promise and observe as he carries out the responsibilities of his office, ‘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.’

When the occasion arose to succeed the President in the early hours of the morning on August 3, 1923, Coolidge did not have to consult a team of legal experts or “brainstorm” with Cabinet members over the telephone about what comes next. He simply consulted the Constitution which sat on his father’s bookshelf and found the oath to be taken by the President, the same he had affirmed over two years before. The answer, to anyone able to read and understand, was accessible simply by looking…