As a historian, what I trust is my ability to take a mass of information and tell a story shaped around it.

The White House is such an extraordinary, simple, beautiful place. It's an extraordinary piece of our history, because it is the one thing that binds our country together. We don't have a king obviously, but we have this president, and the fact that almost all of them have lived in the same place, and so much history took place in those rooms. You can't help but feel awe-inspired by being there.

I think after Sandy Hook, when Obama went out, and he talked a lot about gun control and met with the parents, there was a sense that something was going to happen. But then, I guess, the power of special interests was greater than public sentiment.

There is a sense of feeling larger than your own life when you're in some common mission together. You have to hope it's not going to take a war to bring that back to America again. I think another time when it seemed to be here was in the early 1960s.

There are 20,000 million books I could have to read, but I can pick the ones and know that I'm learning something that I didn't know before. That's the glory of writing. It's not even so much the writing, it's what you learn - especially history - because so much of it is research.

An adult friend of Lincoln's: "Life was to him a school.

I think with Lyndon Johnson, the most important thing I learned was that he never had the sense of security that comes from inside. It always depended on other people making him feel good about himself, which meant that he was always beholden, continually needing to succeed. He could never stop. There was such a restlessness in him.