President Barack Obama made jokes at Donald Trump's expense around Trump's claims on Obama's birth certificate.
Barack Obama is ready to return to frontline politics, according to Eric Holder, who served as Attorney General in the former President's administration.
The suggestion will be welcome in a Democratic Party still struggling to unite in opposition to Donald Trump's presidency after the shock defeat of Hillary Clinton.
WhenObama left office, he said he was prepared to intervene if his successor threatened America's core values - a break in the convention that former presidents are expected to distance themselves from domestic politics.
But whatever move he makes will have to wait until he finishes his memoirs.
Penguin Random House has announced that it won the bidding war for rights to books by the former president and his wife Michelle in a deal believed to be worth more than US$60 million ($83 million).
Meanwhile, Holder said he had been talking to Obama about ways he could help the new National Democratic Redistricting Committee, which the then President asked him to chair.
"It's coming. He's coming," Holder said, according to Politico magazine. "And he's ready to roll."
The committee has been set up to tackle what Democrats see as Republican gerrymandering, offering their opponents an advantage in nationwide and local elections.
Former presidents have found different ways to fill their time after leaving office, setting up foundations and launching themselves into international affairs.
At 55, Obama has plenty more productive years ahead of him. His first priority, however, will be to please his publishers.
Barack Obama and Michelle Obama have signed book deals. Photo / AP
Penguin Random House chief executive Markus Dohle said: "With their words and their leadership, they changed the world, and every day, with the books we publish, we strive to do the same.
"Now, we are very much looking forward to working together with President and Mrs Obama to make each of their books global publishing events."
Whatever the final deal, the price tag for their books will likely shatter the previous record. Bill Clinton made $15 million, and his successor, George W. Bush was paid $10 million.
Obama is a best-selling author already. Critics praised Dreams From My Father, published before he entered politics, for its fluid writing style as he details his early life and search for his roots in Africa.
