Some of the confusion is coming because some of the videos have been doctored. For example, this video has him saying the entire oath, starting about 29:35. The video is mostly footage at the White House. https://www.youtube.com/watch?v=B6Yg6bwllM4 This video has been doctored, with the "preserve the Constitution" section cut out of it, starts about 24:15: https://www.youtube.com/watch?v=RvIgGbgpnQQ+Biden+address&feature=youtu.be This video is mostly the entertainment, with the oath of office thrown in as an afterthought, it appears. The "cut" isn't obvious. Charley Ward said he had received a video of the inauguration at 7am Spain time, which would be about 1am Eastern time. Wonder which version he received? The required oath of the President: "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."