This fourth volume of Robert Caro’s biography of Lyndon Johnson is much like its three prize-winning predecessors, detailed and riveting. Caro has researched Johnson thoroughly: interviewing those who knew Johnson, reading hundreds of other interviews and thousands of documents, scouring the newspapers and the memoirs. The resulting book is long but hard to put down.

Passage of Power covers the period from late 1957 through early 1964. Caro describes Johnson’s curious, ambivalent run for the 1960 presidential nomination; his surprising decision to accept the vice presidential nomination; his effort with Kennedy, like Seward’s effort with Lincoln, to secure more power in the new administration; his frustrating years as vice president; and then, in the last 300 pages of the book, Johnson’s first few days and weeks as president.

Do we learn things from Caro that we did not know from other biographies of Johnson, such as Robert Dallek’s two excellent volumes? Yes, many. Caro tells us, as Dallek does not, that before the 1960 convention Johnson asked his staff an unusual question: How many presidents died in office? Caro relates that when Claire Booth Luce asked Johnson why he wanted such a powerless position, Johnson reportedly responded: “Clare, I looked it up; one out of every four Presidents has died in office. I’m a gamblin’ man, darlin’, and this is the only chance I got.”

Has Caro changed his view of Johnson, a man whom he both despises and reveres? Not a bit. On the one hand, Caro deplores Johnson’s faults and crimes ― how he rigged the 1960 presidential election in Texas and how, over many years, he used his office to secure personal wealth. On the other, Caro relates in great and gushing detail how Johnson secured passage of the Civil Rights Bill of 1964. “To watch Lyndon Johnson deal with Congress during the transition … is to see a President fighting not merely with passion and determination but with something more: with a particular talent, a talent for winning the passage of legislation (in this case legislation that would write into the books of law a measure of justice for millions of people to whom justice had been too long denied) that was more than a talent, that was a gift, and a very rare one.”

Does Caro’s new book, as reviewers have said of his earlier  books, “read like a novel?”  Yes and no. When it works, Caro’s prose style is wonderful; his alternating long and short sentences, his repeated phrases and quotations, make the book immediate and powerful. But when it does not work, Caro’s prose style is annoying, forcing the reader to go back, at the end of a hundred-word sentence, to remind himself of the subject.

Is Caro’s book solid and supported? Not always. There are simple statements of fact and quotations without sources. For example, on the next to last page of the book, Caro states that perhaps 2 million Vietnamese were killed in the war, “some by bombs dropped on villages selected as targets by Johnson himself.” There is no note for these statements. In the section of the book on the late 1950s, Caro states that “newspaper articles were beginning to appear about Bobby Kennedy now. In describing him, many of them used the same adjective: ‘ruthless.’ Bobby Kennedy hated that adjective.” One would think that this would be supported by newspaper articles, as well as evidence that Bobby Kennedy disliked being called “ruthless.” Yet in the 60 pages of notes at the back of the book, there is no note for these sentences. Other books about Bobby Kennedy, such as Evan Thomas’s biography, agree that Kennedy was ruthless but not that the press was calling him ruthless at this time, an important distinction.

Later, Caro describes how Vice President Johnson was snubbed at the White House and excluded from Washington dinner parties, a section of the book for which Caro provides no notes at all. This, I hope, is an editing error that can be fixed in the next printing. These are only three points of several where it seemed the notes did not support the text.  To evaluate fully would require retracing all Caro’s steps, a task that would take many months, a task that would be made more difficult because Caro does not use standard numbered notes; he uses snippets of text as identifiers, without page numbers.  However, if one reviewer can notice a few such points in a first read, it seems likely that a thorough review would reveal more such issues, and raise questions about the extent to which Caro’s narrative is adequately supported by his sources.

Let me not conclude on a negative note, however. There are passages in this book that, once read, will never leave the reader, especially Caro’s description of the day of JFK’s assassination. Caro describes not only the events in Dallas from Johnson’s perspective, but also events in Washington, where a Senate committee was hearing testimony against Johnson, and in New York, where Life magazine was preparing articles on Johnson’s questionable wealth. This section of the book is like a movement in a symphony, in which several themes, both dark and light, are woven together and come to a stirring conclusion as Johnson takes the oath of office. It is for passages such as this that one reads biography and why one should read this great book.

Walter Stahr is a Washington lawyer and the author of John Jay: Founding Father (2005) and Seward: Lincoln’s Indispensable Man (September 2012).