This Friday, January 20, at about noon local time, Donald Trump will take the oath of office to become the 45th president of the United States.
As set out in the U.S. Constitution, the following is what the president-elect Trump is supposed to recite when he is sworn in by Chief Justice of the United States John G. Roberts, Jr.:
"I ... do solemnly swear (or affirm) that I will faithfully execute the Office of the President of the United States, and will to the best of my ability, preserve, protect and defend the Constitution of the United States."
(Many presidents also add the phrase, “So help me God.”)
While the oath seems simple enough to administer, mistakes have happened.
Case in point: President Barack Obama's first inaugural ceremony in 2009.
As an estimated crowd of 1.8 million people packed the U.S. Capitol area on that cold January morning for the historic event, which was broadcast on television and radio, and live-streamed on the internet, Chief Justice Roberts misspoke, first, by transposing one of the words.
Listening closely, one can hear that the chief justice misplaced the word “faithfully” when he said, “That I will execute the office of president to the United States faithfully.”
Obama paused awkwardly after saying, “that I will execute.” The chief justice gave it another try, but the oath still was not quite right. Roberts omitted the word “execute.”
The next day, Chief Justice Roberts, who could be seen and heard saying to the president that it was “my fault,” went to the White House and the two men went through the ceremony a second time.
Later, the White House released a statement, saying the redo took place out of “an abundance of caution.”
One other notable detail of that day: that hat:
Four years later, Obama’s oath, administered again by Roberts, went off smoothly for the most part. The president stumbled almost imperceptibly at one point. See if you can pinpoint it.