Legacy is what a president does that affects later generations.

A lot of it was, you know, you look for moments where, for instance, we were dependent on Abraham Lincoln making sure that the slaves were freed or John Kennedy bringing civil rights, or the first one I wrote about, George Washington trying to stop the British from invading and ending this country before it even began. Those were turning points where, if you had not had a president stepping up to the plate, if there wasn't a story like that, we would not be here.

First of all, there's no mention of political parties in the Constitution, so you begin American history with not only no political conventions but also no parties.

Lincoln was able to say, you know, "It will make me very unhappy if I lose the presidency, but I'm committed to larger things." If you look at candidates and say this is someone who can be happy to go back to their family or they have larger convictions. Franklin Roosevelt jeopardized his presidency by telling Americans in 1940, "We might have to fight Hitler." He loved being president, but he loved defending freedom more.

You have to raise $100 million, probably, to be serious.

As you look back in history, we [the United States] have done wonderful things, the Marshal Plan is the most obvious. After World War II, we spent billions of dollars to rebuild Europe or at least part of Europe after the devastation of World War II. We did it out of charity, but we also did it to keep the Russians from getting deeply into Europe.

I'm defining [presidential courage] pretty narrowly. It's not only taking a big political risk but it's also the risk that in the hindsight of history, people think it's wise.