President Donald Trump took the oath of office on Jan. 20 at the Capitol. (The Washington Post)

Donald Trump on Friday came to the Capitol, where he placed his left hand on an old Bible, raised his right hand and repeated 35 words (plus his full name) read by Chief Justice John G. Roberts Jr. from the Constitution.

“I, Donald John Trump, do solemnly swear 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,” he promised the American people, as prescribed by Article II, Section 1 of the Constitution, just as the presidents before him have done.

What makes the words so unique is that the incoming president is the only one required to declare them. Although the Constitution specifies that the vice president and other government officers should make vows, it does not stipulate what exactly they should say.

As The Washington Post’s Fred Barbash reported earlier this month:

No specific oath is required for anyone else — Supreme Court justices, members of Congress or any other officer of the federal government. They are all lumped into Article VI: They ‘shall be bound by Oath or Affirmation, to support this Constitution . . .’

(The Bible is optional for all officers of the government.)

The framers left no record of why they thought the presidency worthy of its own special incantation, except that one delegate, James Wilson, said he thought it redundant, given Article VI.

George Washington, who they all knew would be the first president, was sitting right there as president of the Constitutional Convention of 1787 so maybe it was some kind of a tribute, to make him feel special and guarantee that he would take the job.

They tinkered with the language. The president ‘shall swear fidelity to the union . . . by taking an oath of office,’ was an early version. It was replaced by ‘I will faithfully execute the office,’ which was, in turn, augmented by ‘and will to the best of my judgment and power preserve, protect and defend’ the Constitution, and then, finally the version that exists now.

What the framers were thinking at the time is a mystery.

For his swearing-in ceremony, Trump had said that he would use either his childhood Bible or one President Abraham Lincoln used when he was sworn into office more than 150 years ago.

During the 58th presidential inauguration, Trump followed in a long line of presidents to repeat the oath on the West Lawn of the Capitol.

The oath of office is administered to each president during inauguration ceremonies, marking the official beginning of the new administration. (Peter Stevenson/The Washington Post)

Vice President Mike Pence also took an oath — a longer version that has been used since 1884, according to the Joint Congressional Committee on Inaugural Ceremonies.

“A variety of officials have administered the oath to Vice Presidents,” the joint committee says. “The president pro tempore of the Senate administered the oath to the first three Vice Presidents — John Adams, Thomas Jefferson, and Aaron Burr — and to many Vice Presidents from the mid-nineteenth century to the early twentieth century. Some Vice Presidents took the oath from the Chief Justice. On some occasions, the outgoing Vice President administered the oath to the Vice President-elect. Since World War II, Vice Presidents have chosen friends and associates to administer the oath of office.”

Pence used the Reagan family Bible, which he said he would open to II Chronicles 7:14, the same scripture Reagan used, according to The Post’s Katie Mettler. It reads: “If My people who are called by My name will humble themselves, and pray and seek My face, and turn from their wicked ways, then I will hear from heaven, and will forgive their sin and heal their land.”

Then, Supreme Court Justice Clarence Thomas led Pence in his declaration.

“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,” he said, shortly before Trump was sworn in.

In 2009, Barack Obama and Roberts stumbled through the presidential oath — and did it over again in the White House the next day, “just to make sure,” The Post reported at the time.

“We decided it was so much fun,” Obama had said jokingly.

Then he walked over to Roberts and raised his right hand.

“Are you ready to take the oath?” Roberts asked.

“I am — and we’re going to do it very slowly,” Obama replied.

The White House later said in a statement that the sacred oath was re-administered “out of an abundance of caution.”

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