Anchored by Jake Tapper, The Lead airs at 4 p.m. ET on CNN.
U.S. Ambassador to Ukraine Geoffrey Pyatt. Plus, a look at Vladimir Putin's international image.
New book "Double Down: Game Change 2012" dishes behind-the-scenes drama from the 2012 presidential election, like how President Barack Obama's mock debate performance was described by one of his debate coaches as "creepy," and led to an intervention.
New Jersey Governor Chris Christie said he was disappointed that some of the documents of his vice presidential vetting process were leaked to authors John Heilemann and Mark Halperin.
"We did 500 interviews for this book with more than 300 people," Heilemann said in an interview with "The Lead with Jake Tapper." "There are clearly people who have agendas, they cut in every different possible direction, and ultimately our job is to sort through people's agendas and try to get at what's true."
"In the case of Governor Christie and the vetting report ... we quoted extensively from the final vetting report as it was written," said Heilemann.
"The motivation of the source or sources of that document is kind of irrelevant, it's on paper what the vetting committee was concerned about, and what its worries were about Governor Christie's – the unanswered questions from his vet, the matters that were in the public record but not widely known in the national political press corps – and that they conveyed to Governor Romney those concerns and Governor Romney pulled the plug the next day, and that is the fact of what happened," said Heilemann.
When the authors' first book, "Game Change," came out, lost in all the drama about the Mccain-Palin campaign was the fact that the Obama team did not dish much. This time, when it came to leaks the White House was a veritable colander.
"We got a high degree of cooperation from people inside the White House, from people in President Obama's re-election committee in Chicago," said Heilemann. "We also got a wide degree of cooperation from all the Republican candidates and from Governor Romney staff."
Heilmann and his co-author Mark Halperin also had the benefit of time; they had three years to work on "Double Down."
"Over the course of time, we were able to get pretty far inside. We're pretty proud of that. I don't think there were people in the White House who were setting out obviously to make the president look bad, but one of the jobs of reporting ... is to kind of get at the truth," said Heilemann.
"When you're talking to enough people, eventually the truth starts to make itself known. And sometimes that's not totally flattering, but in some cases, it is humanizing for a president that for a lot of people still remains a kind of distant and somewhat remote figure," said Heilemann.