[on the relationship between Theodore Roosevelt and William Howard Taft] Taft was Roosevelt's handpicked successor. I didn't know how deep the friendship was between the two men until I read their almost four hundred letters, stretching back the to early '30s. It made me realize the heartbreak when they ruptured was much more than a political division.

Roosevelt coined the phrase 'bully pulpit' for the platform a president has to influence public sentiment. 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.

Those who knew Lincoln described him as an extraordinarily funny man. Humor was an essential aspect of his temperament. He laughed, he explained, so he did not weep. His 'eyes would sparkle with fun', one old-timer remembered, 'and when he had reached the point in his narrative which invariably invoked the laughter of the crowd, nobody's enjoyment was greater than his'. His ability to counter criticism with humor was legendary. When told that he was two-faced, he instantly responded, 'If I had two faces, do you think I'd be wearing this face?'

Although Lincoln's voice was 'thin' and 'high-pitched', reporter Horace White recalled, it had 'much carrying power' and 'could be heard a long distance in spite of the bustle and tumult of the crowd'. While he seemed awkward at first, when he 'hit his stride', White observed, he grew 'very impassioned' and 'seemed transfigured' by the strength of his words.

Lincoln's singular way of walking, contemporaries observed, gave the impression his long, gaunt frame needed oiling. He would plod forward in an awkward manner, his hands hanging at his sides or folded, behind his back. His step had no spring, his law partner William Herndon recalled. He lifted his whole foot at once and then thrust it down on the ground rather than landing on his heel. 'His legs', another observer noted, 'seemed to drag from the knees down, like those of a laborer going home after a hard day's work'.

A lot of times when people are on campaigns, it can be like a movie set.