We are here this evening as the nation prepares to witness the moment that comes once every four years, the presidential inauguration. The constitution requires the inauguration to be held on JANUARY... See More
We are here this evening as the nation prepares to witness the moment that comes once every four years, the presidential inauguration. The constitution requires the inauguration to be held on JANUARY 20th, BUT BECAUSE THE Day is sunday, the nation will see it play out tomorrow just behind me at the capital. Quietly today, chief justice john roberts administering the oath of office in a private ceremony. The first lady holding her grandmother's bible. Their daughters by their side. All around washington tonight, there's a growing buzz in the air as they get ready. The u.S. Marine band rehearsing on the capital steps a short time ago and where the president will deliver his inaugural address tomorrow. Authorities are expecting 800,000 people to gather here, a massive number for a president ushering in a second term. We have our team across washington tonight. We begin with the quiet ceremony at the white house and her chief white house correspondent jonathan karl. Reporter: It was short and sweet. Just 42 words. So help me god. Reporter: With that, the seconds term begins. Last time around chief justice roberts flubbed the words. Execute the office -- Reporter: This time he took notes. Tomorrow, president obama will tie a record, taking the oath for the fourth time. There was a flubbed one four years ago, a redo the next day. Today's official oath required by the constitution to be done before noon on january 20th and the ceremonial one tomorrow before his inaugural speech. Many oaths since fdr, he was elected four times. The challenge for president obama this time is to recapture the energy and enthusiasm of four years ago when a record 1.8 million people descended on washington to witness the history-making swearing-in of the nation's first african american president. Nobody expects a crowd that big again. This time, the president will have his hand on two bibles. Abraham lincoln's and martin luther king's. A video released by the white house, the president explained why. Letting them know there's a connection between me being here, the sacrifices of those in the past, which I think is entirely fitting. The man who ran obama re-election campaign says the president will use his big speech tomorrow in part to reach out to some of those who voted against him. You'll see a president who wants to work across party lines to get things done. I think that's what the country wants. Reporter: After today's oath was complete, the president's 11-year-old daughter was happy to see dad got the words right. I did it. You didn't mess up. And jon karl is with us. The chief justice bringing notes with him to the white house. Not going to mess up this time. The president made history here four years ago. A lot at stake. What does he have to accomplish tomorrow? This is a chance to set the tone. It's not a policy speech. But this is a huge audience, maybe the second biggest audience of his presidency. He wants to set a tone and to reach out to some of those who voted against him.
This transcript has been automatically generated and may not be 100% accurate.