Obama officially begins his second term with oath "Congratulations, Mr. President," said Roberts. "Thank you, Mr. Chief Justice," Obama replied. Thank you so much. He then kissed his wife, whom he called "Sweetie," and told his daughters, "I did it." Obama's hand rested on a Bible that Michelle Obama's father Fraser Robinson III had given to his mother, LaVaughn Delores Robinson, on Mother's Day 1958. Obama and Roberts will repeat the process again Monday in a public celebration at the Capitol. The Constitution mandates that presidential terms begin on Jan. 20, and it is traditional when the day falls on a Sunday that the public ceremony take place the next day. The brief ceremony - from the family's entrance to the handshakes and kisses that marked departure took less than a minute and a half - followed a morning where the president took part in a wreath-laying ceremony at Arlington National Cemetery and worshiped at a historic African-American church. Vice President Biden got a jump on the president by taking his oath at an early-morning ceremony at his residence at the Naval Observatory. Justice Sonia Sotomayor swore Biden in, becoming the fourth woman and the first Hispanic to administer the oath to the president or vice president. Biden was sworn in before a crowd of 120 people, surrounded by his family on a makeshift stage in an alcove. After the oath was completed, Biden kissed Sotomayor and then hugged and kissed his wife, Jill Biden, who held a massive Biden family Bible. "Madame Justice, these are some of my friends, and family," Biden said, grasping Sotomayor's hand. The 8:21 a.m. event apparently was prompted by Sotomayor's need to be at a Barnes and Noble in New York for an afternoon address and signing event for her new memoir, "My Beloved World." Biden didn't get into specifics, but told the crowd: "I want to explain to you what a wonderful honor it was, and how much out of her way the justice had to go. She is due in New York. She has to leave right now. . .so she can catch a train - I hope I haven't caused her to miss. Biden's ceremony led to speculation about his political future--a wide range of Democratic officials, early primary state officeholders and party strategists were on hand. Among the invited were former White House chief of staff William Daley, Obama's longtime political strategist David Axelrod, New Hampshire Gov. Maggie Hassan, House Democratic leader Nancy Pelosi and Democratic National Committee Chairwoman Debbie Wasserman Schultz. "Of course we can always start the political calculations in terms of the number of delegates needed to secure a nomination," said longtime Democratic strategist Donna Brazile, who was also in the crowd. But let's just say I see a number of superdelegates here as well.