On the importance of TR befriending Booker T. Washington: "They show his courage, which I think is an essential quality of great presidents. It was just about his very first political act of any consequence. Within weeks of becoming president, in the fall of 1901, he invited Booker T. Washington to dinner at the White House.
"And even before that he was consulting with him on Southern patronage. By inviting Washington to dinner, he ignited an explosion of racial paranoia in the white, Democratic South. So for a vice president to become president and immediately execute an act of such moral courage, I think, is a testimony to his essential greatness as a president."
On what lesson modern-day Republicans can draw from TR: "I don’t think I can answer that. I’m more interested in individual presidents and their behavior as men. Questions of party politics and party policy don’t interest me very much."
On whether he grew weary of TR during decades of research and writing: "Not while I was writing about him. Of course, during those 30 years, I spent 14 years writing about Reagan and almost two years writing about Beethoven. So I had plenty of time off.
"But I never got tired of him simply because he was such a polychromatic character. He was not just a politician. He was a man of letters, he was a soldier, he was a scientist, he was all those other things. And he had the essential quality of charm, which was related to his humor. It was one of the reasons I never got tired of him. One could very quickly get tired of a substantial president who had no humor."
On the contrast between TR and Reagan as subject: "Although they were extremely different people, they did have several qualities in common. One is the humor. Reagan was also a very funny man. And, secondly, they both had drama. Reagan was an actor and TR, too, was a master of presidential drama.
"If a president does not have the gift of theater, which both of these men had, they almost invariably don’t succeed.
"I was not drawn to either man because he was president. I was, in each case, drawn to these guys because of the enduring fascination of their character. And their life stories."