By the 1930s, he had earned a reputation as a creator of beautiful parks in both the city and state, and later long-sought projects like the Verrazano Narrows Bridge, but at the price of his earlier integrity. Caro ultimately paints a portrait of Moses as an unelected bureaucrat who, through his reputation for getting large construction projects done, amassed so much power over the years that the many elected officials whom he was supposedly responsive to instead became dependent on him. He consistently favored automobile traffic over human and community needs, and while making a big deal of the fact that he served in his many public jobs (save as New York City Parks Commissioner) without compensation, lived like a king and similarly enriched those individuals in public and private life who aided him.
While Caro pays ample tribute to Moses's intelligence, political shrewdness, eloquence and hands-on, if somewhat aggressive, management style, and indeed gives full credit to Moses for his earlier achievements, it is clear from the book's introduction onward that Caro's view of Moses is ambivalent (some of the readers of The Power Broker would conclude that Caro possessed only contempt for his subject).
At 1336 pages (reputedly edited from a manuscript three times that length), it provides documentation of its assertions in most instances, which Moses (and his supporters after his death) have consistently attempted to refute. Because Caro's narrative includes a great deal of history about New York City itself, the book is considered by many to be a monumental scholarly work in its own right, transcending the normal style of a biography that focuses on the life of a single person.
Moses's influence on New York City was undisputed, even though his political power had been cut off, and as it was shortly after President Nixon's unprecedented resignation, the public was receptive to accounts of public officials absolutely corrupted by the power they had attained. It received favorable reviews, and brought a host of forgotten scandals to new light, as well as some new ones (Moses's shameful treatment of his brother, for example) though some critics felt that Caro's insinuation of an extramarital affair between Moses and Manhattan congresswoman Ruth Pratt was a bit too gossipy and salacious for such a serious book.
It became a bestseller and won the Pulitzer in biography for that year, as well as the Francis Parkman Prize awarded by the Society of American Historians to the book that best "exemplifies the union of the historian and the artist." It has remained in print ever since. In 1986 it was recognized by the American Academy and Institute of Arts and Letters, and in 2001 the Modern Library selected it as one of the hundred most important books of the 20th century. In 2005, Caro was awarded the Gold Medal in Biography from the American Academy of Arts and Letters. David Klatell, dean of the Columbia University Graduate School of Journalism, has recommended the book to new students to familiarize themselves with New York City and the techniques of investigative reporting.
Moses and his supporters considered the book to be overwhelmingly biased against him, to the point that Moses put out a 23-page typed statement disputing some of its assertions (he claimed he never used the anti-Italian slurs the book attributes to him about Fiorello La Guardia, for instance) and what his supporters saw as a record of unprecedented accomplishment.
In later years, some further criticisms have been made of the book, mainly that it overstates the extent of Moses's power in the 1960s. In the 21st Century, as many have decried the inability of American public institutions to construct and maintain infrastructure projects, a more positive view of Moses' career has emerged. In a 2006 speech to the Regional Plan Association on downstate transportation needs, Eliot Spitzer, who would be overwhelmingly elected governor later that year, said a biography of Moses written today might be called At Least He Got It Built. "That's what we need today. A real commitment to get things done".
He found that despite the man's illustrious career, no biography had been written, save the highly propagandistic Builder for Democracy in 1952. So he decided to undertake the task himself, beginning the seven-year process of hundreds of interviews meticulously documented as well as extensive original archival research, listed in the notes on sources in an appendix to the book.
Moses "did his best to try to keep this book from being written -- as he had done, successfully, with so many previous, stillborn, biographies." (The Power Broker, p.1167). After Mr. Caro had been working on the book for more than a year, he agreed to sit for a series of seven interviews, one lasting from 9:30 A.M. until evening, providing much material about his early life, but when Caro began asking questions ("for having interviewed others involved in the subjects in question and having examined the records, -- many of them secret -- dealing with them, it was necessary to reconcile the sometimes striking disparity between what he told me and what they told me") the series of interviews was abruptly terminated." (The Power Broker, p.1167, quoted with permission). Moses's brother Paul was about to provide Caro with the reason behind their decades-old family feud, but died of a heart attack hours before he could explain.