text:  We're republishing The New Yorker's long excerpt at newyorker.com. Robert Caro, of course, went on to an even bigger project, his series of books on the life of President Lyndon Johnson. A few years ago, Caro took a break from that research to talk with me at the McCarter Theater in Princeton, New Jersey. A book of shorter pieces about his working method, a book called Working, had just been published.