You start with this famous study of Abe Lincoln. 

This is just about the best book on politics I’ve ever read. You have to be a bit careful because with somebody like Lincoln there is such mass of material out there, but what Doris Kearns Goodwin has managed to do is to give it a freshness and a depth that is very rare – it’s an unputdownable historical account. It is called Team of Rivals because it is Lincoln’s story but also the story of the three people who were his rivals for the presidential nomination – it’s their stories all interweaving, plus a fifth main character, this guy Edwin Stanton, who had absolute contempt for Lincoln, as did the others at different levels and at different stages. They just didn’t see him as this great figure that he’s now seen as. He was a backwoods lawyer from Illinois, I think he’d only been one term in the House of Representatives, and he’d lost a couple of elections to the Senate. If you are interested in political campaigns… As I read it I was thinking, ‘God, what would these guys be like today, or what would we be like back then?’ 

Just think about campaigning for the presidency of the United States. In the television age, and with aeroplanes and all the rest of it, it’s quite straightforward but it’s still bloody hard. It’s incredibly gruelling. Well, these guys are spending all their time travelling. 

Some of the most extraordinary things she gets are actually in the letters they write. Today, if you’ve got a message to deliver you go on the telly or you buy an advertising spot or something. These guys used to write to people: literally, ‘Dear Mr Bloggs, I am blah blah…’ Then, of course, they would have these big public meetings and they would often be in the same areas – they were always sleeping in the same rooms and talking about their affection for one another. This was a totally different political era where the relationships between the political figures themselves were so much richer and more entwined. I mean, imagine before the TV debates if Brown, Cameron and Clegg had been sharing a room.

There’s an amazing account of the nomination campaign of these three: William Seward, Salmon Chase and Edward Bates. If you had had political bookmakers back then, Lincoln would have been fourth favourite. This has an incredibly detailed account of how he turned it round and how he won. And then he gave all the top jobs to his rivals, like Obama in making Hillary Clinton Secretary of State. 

Isn’t this famously Obama’s top book choice? 

Yes, he said if he had to take only one book into the White House this would be it – although he also chose the Bible, which they always have to say. 

So Seward became Secretary of State, Bates became Attorney General and Chase became Treasury Secretary. And then this other bloke Stanton, who had been vile about Abe Lincoln, used to call him a baboon and a long-armed ape and all this sort of stuff, he became Secretary of War. So he built his team around them. And then during his presidency, particularly at the time when the country was in a state of civil war, his political genius, as the book calls it, was holding all these factions together. 

Now, some of them he gets rid of. Chase kept threatening to resign and in the end he called his bluff and got rid of him. Basically, Lincoln got the nomination and Chase thought it might not go so well so he kept manoeuvering to get the nomination next time around, and eventually Lincoln got rid of him. But the rest of them adored him. 

Of course all these guys were better educated and more experienced, but they all said by the end – this guy is like the nearest we’re going to get to perfection in a human being. There is no doubt that he had a political genius that was not apparent when he first came on the scene. In a way I guess Obama, whom people thought looked like the most amazing thing... 

Obama has a trajectory going in the other direction? 

Yes. And Lincoln was dealing with a collection of such difficult issues. There is so much detail in the book about him and his family. And again, which interests me, he was a depressive. She’s got a lot about that, about his moods and his melancholia, as they called it. It’s funny, I often wonder about these guys when they were part of it, whether they knew how history would be written. If you say to most people ‘Lincoln’ they will know. But Seward, Chase and Bates? Lincoln has become the figure in history for that period and yet they were a very, very important part of what he achieved. 

And the whole idea about leadership, I think, is not just about the leader but about the team that you build and how you use the different skills of the people around you. And there are an awful lot of lessons in it for people in politics today. And, as with Churchill, another depressive, how would he have coped now? It is interesting to speculate what Churchill would have been like with the 24-hour media? What would Lincoln have been like? It has created this extra layer. Because what you get from this and from the Churchill biographies is the sheer scale of stuff that they are dealing with at all times. Now, so are modern politicians, but we look at them in a completely different way because there is this bloody television blaring away 24 hours a day. 

If somebody brings in their rivals is often seen as a clever tactic but you are arguing that it is actually a good idea to bind those people together for the sake of their strengths? 

Partly, people get strength within an organisation by challenging or by standing for leader, then they win a place in the leader’s team of rivals.