A casual observer could get the impression that Caro started writing his multi-volume biography, The Years of Lyndon Johnson, because he had some deep and abiding interest in LBJ. That's not just because he's devoted several decades and thousands of pages to the subject, but because he seems to be in the character-as-destiny camp. Power may corrupt, but it always reveals, as he says in the most recent volume, and what is revealed shapes the destiny of the character in question and the character's entire field of influence (which is, in the case of LBJ, the entire country).
Yet as Caro has said before, he was never drawn to LBJ because of any particular interest in LBJ, or in big names more generally. Rather, his interest is in political power: how it can be acquired, and how it can be used. As he described it tonight, the first four volumes of the LBJ biography are framed around aspects of this question: the power of rural politics, in The Path to Power; stealing elections as a way to get power, in The Means of Ascent; the wielding of legislative power, in Master of the Senate; and now, the transition to the power of the presidency during a moment of national crisis, in The Passage of Power.
The fact that this is why Caro took an interest in Johnson is, perhaps, one of the factors that puts him in a separate category from the other people who have written at length about LBJ, or for that matter, the Kennedys. The other biographers, that is, have often had some kind of emotional investment in the person. As an outlying example, here's Doris Kearns Goodwin, describing how Johnson used to come into her room before dawn to talk: "His voice on these occasions was soft, so soft, it was sometimes hard to understand but on this morning the pain and sadness in his tone was so striking that I forced myself to comprehend every word."
That level of intimacy is a little unusual in a political biography. But so too is Caro's more detached approach--unsurprisingly, on balance. How often does it happen that someone writes an epic biography of a major historical figure not because they have a strong opinion about the person in question, or about the consequences of his actions, but because they happen to be interested in an abstract concept that the figure in question experienced and projected in interesting ways? It's like writing 4000 pages about Genghis Khan because his life strikes you as a useful prism through which to examine the nature and limits of religious pluralism.
As for Caro, one thing he did seem to care about deeply was process. He had an understated affect when asked directly about it He doesn't have a computer in his office, he said, but if there is a need to Google something, his wife, luckily, is a computer genius. But at several points he elaborated on research and sourcing considerations in a way that suggested the subject was close to his heart. It was lucky that Johnson had two aides with him on the day that he first met Robert F Kennedy, because that interaction was so revealing, and really set the tone for what was to come; but he only uses a story if he has two sources for it, so it was the fact that he talked to both of the aides in question, and they both described the same instant animus between the two men, that allowed the story to be retold. Despite all the billion biographies of Kennedy, and the intense focus on that day in Dallas, nobody had ever looked at what Johnson was doing from the moment the motorcade heard the first crack of the rifle, so he, Caro, had a chance to do it; it wasn't a great research job on his part, he continued, because he didn't have to dig very far, he just went to the LBJ Library and asked them if they happened to have a copy of the incident report that the Secret Service Agent Rufus Youngblood, the one who threw Johnson to the backseat of the third car and covered him with his body, would have filed, and sure enough they did. It was in a grey binder. Knowing what he knows now, he was asked, is there anything he wishes he could change about the earlier volumes? No, he said.