[Lyndon ] Johnson was responding to a black freedom movement that was tearing the country open and he did what he had to do as a conservative politician.

Andrew Breitbart, self-described media mogul, had several screws loose or missing and was the grinning bomb-thrower of the radical right. He was the attack dog kept on a tight leash and brought out on special occasions to hiss and to menace.

Every politician - FDR, Lyndon Johnson, Abraham Lincoln, Barack Obama - they're all conservative by nature. They are part of the big thing and they're moving in a very constrained world.

Let's look at two things real quickly: the civil rights movement in Mississippi in the Sixties and the Arab Spring starting in Tunisia and Cairo. What they had in common was people who were told, and who believed inside themselves, that they were a certain way, and the society at large believed it.

All that means to me is that people who have a vision of a better world have a responsibility to open their eyes, to pay attention, to act on what the moment demands, and to be humble about that action.

Part of the fun of writing, touring, teaching, is engaging with real people about all of it: what to do now, how to build a movement, of approaches to teaching, of parenting - it's exciting to be in that dialogue.

Martin Luther King was only an activist for 13 years and every year he changed and every year he became more radical. By the end he was calling for revolution. People don't know this because they go to too many prayer breakfasts on his birthday.