When considering Spitzer, two lines of questioning present themselves. First, to what extent is he driven by vanity–by an awareness of his image as a square-jawed crusader playing for keeps on a giant stage, an Eliot Ness-like figure who avenges the small investor by fearlessly taking on Wall Street fat cats, who heretofore existed beyond reproach and retribution? Second, how far can this man go, and to what extent is he willing to compromise his core principles and values to get there?

Masters, a reporter for The Washington Post, provides a wealth of material to begin attempting an answer to both these questions. In a nutshell, she argues that Spitzer is pursuing traditional progressive ends with prosecutorial means, all the while carefully modeling his progressivism on historical figures (Republicans included) in a way that tidily insulates him from charges that he’s an old-style anti-business Democrat. She was granted extraordinary access both to the man himself and to the inner workings of his sprawling operation, and this has enabled her to shed fresh light on his thinking and to contextualize him historically in a way that makes us see him anew.

As Masters points out, Spitzer himself has written that the future of the Democratic Party depends on its ability “to promote government as a supporter of free markets, not simply a check on them,” and to hew to “a vision consistent with trust-busting and other progressive market measures first enunciated early in the last century by Theodore Roosevelt.” Which is exactly what Spitzer has done. In interviews with Masters, Spitzer seeks to cast himself not as coming from a populist tradition, but as operating within the tradition of Theodore Roosevelt and the Progressives–indeed, he keeps a framed photo of Roosevelt on the wall of his office. “I invoke him for the notion that capitalists understand when the market needs to be tamed,” Spitzer explains. Like Roosevelt, Spitzer doesn’t see himself as an antagonist of the free market, but rather as its defender against those who would game and corrupt the system. And he is quite explicit about the fact that he sees this not just as good policy, but good politics–particularly for Democrats, and for himself.

Though the position of New York attorney general has boasted energetic figures in the past–from Louis Lefkowitz to Robert Abrams–the job nonetheless has generally been a bureaucratic and legal backwater, hardly the kind which can bring national prominence, let alone international renown. And yet, upon winning election to the post in 1998 after dethroning the forgettable GOP incumbent Dennis Vacco, Spitzer transformed the position with amazing speed. How he did this–and how he engineered his rise–is a story that is told in this book with a great deal of dramatic detail. After a quick dip into his privileged past, upbringing, and early career–Horace Mann, Princeton, Harvard Law School, a stint in the Manhattan district attorney’s office–we’re taken through Spitzer’s first failed attempt at winning the attorney general’s seat in 1994, his successful bid four years later, and his initial efforts to expand the office into something commensurate with his ballooning ambition.

Two things are striking about this part of the tale: his constant efforts to resurrect old, quasi-abandoned statutes to pursue current ends, and the relentlessness with which Spitzer moved to expand the office in new ways that trampled on the bureaucratic turf of others. One story, oft-told elsewhere but well-related here, involves Spitzer’s successful effort to crack down on financial fraud by dusting off the Martin Act–an old statute whose amendments give attorneys general civil investigative powers, such as the ability to issue subpoenas or question brokers and investment bankers. The book also takes us behind the scenes to witness the legal brinkmanship of Spitzer’s highest-profile cases–his pursuit of Merrill Lynch; the targeting of Richard Grasso, the former chairman of the New York Stock Exchange with the gargantuan retirement package of $139.5 million; and his assault on Hank Greenberg, the venerable American International Group executive. Each episode provides an up-close view of Spitzer wrestling internally with the fact that his power and visibility are growing at a dizzying rate. The Spitzer presented here is someone who’s constantly grappling with how far to go in applying his expanding clout without abusing it or damaging his carefully constructed crusading image.

At one moment we see Spitzer finally deciding against the prosecution of a very high-profile executive after “a couple of anguished jogs around the reservoir in Central Park.” In another fascinating scene, Spitzer is preparing to give a speech to top research analysts, and he’s privately resolved to give a very critical and aggressive address wholly out of sync with the gathering’s celebratory tone. Just before the speech an aide approaches and suggests toning down the remarks, but Spitzer refuses. The result is a disaster, with Spitzer coming across as overbearing and drunk on his growing clout.

Indeed, Spitzer does display an ugly side–a relish of confrontation, a lust for the spotlight–as he gropes his way towards an understanding of the potential and limits of his growing power and visibility. Here and there, Spitzer and his cavalry of legal jousters come across as power-crazed bullies. In one instance, two Spitzer lawyers give an executive 24 hours to plead guilty, threatening if he doesn’t to arrest him at home in front of his child and pregnant wife. In another, an exec is sent to jail despite his bond with his severely disabled daughter.

It is in Spitzer’s overzealous prosecutorial streak that we can, with Masters’s help, begin to locate an answer to our opening question: To what extent is Spitzer driven by vanity? The unmistakable conclusion, at least from Masters’s telling, is that Spitzer has occasionally been carried away by an awareness of himself as a crusader who can strike fear into a whole industry with the simple wave of a subpoena. This invites comparisons, Masters says, with Rudy Giuliani, the former U.S. attorney and New York mayor whose prosecutorial streak led him to bully all manner of weak constituencies in his quest to clean up Gotham. But the comparison is only partly valid. The hectoring tendency in both men is rooted in fundamentally different impulses. And it’s this difference, I think, which ultimately explains Eliot Spitzer.

Giuliani’s overzealousness is driven primarily by a lower-middle-class white resentment that was widespread in the New York City of the ’60s and ’70s, when rising crime and the city’s dire fiscal situation turned it into a racial tinderbox. His prosecutorial streak is an avenging one rooted not in ideology but in (not entirely unjustified) hatred of urban disorder. Spitzer’s zealousness, on the other hand, is far more ideological. It’s driven by a genuine progressive concern–a desire not for order and safety, but for fairness. Though Spitzer strains to avoid being labeled “populist,” all of his crackdowns–whether on people committing financial fraud, unfair labor practices or environmental violations–are animated by a traditionally liberal impulse to level the playing field for small investors, workers, and those subject to excessive environmental depredation, among others. Indeed, it isn’t too much of a stretch to say that Spitzer has, whether by accident or by design, crafted a unique politics all his own: prosecutorial progressivism.

In sum, if Spitzer does overreach, if he is occasionally carried away by his own white-knight image, he’s still a man who’s at bottom fundamentally fair-minded and genuinely committed to effective public service. In some of the best parts of the book, Masters lets Spitzer defend himself against the charges of overzealousness so often directed his way. His overriding defense is to suggest that one should be impatient when governmental institutions fail, one should push and strain and trample on others if it’s necessary to get those institutions working again; one shouldn’t be overly respectful of bureaucratic turf boundaries if they’re standing in the way of getting things done.

Spitzer’s energetic impatience with the status quo has succeeded brilliantly for him in political terms, which is why he has an overwhelming lead in every poll to be the next governor of New York, a traditional jumping-off point for higher office, including bids for the presidency. But should Spitzer become governor, and should he bring to that position the same impulse towards reform, he’ll face a whole new set of challenges. He’ll be doing battle not with a financial elite, but with a political elite–much of which is in Spitzer’s party–which has been dominant for decades. Becoming governor will require a whole new set of compromises, many of them with people who should be targets of his presumed efforts at reform once in office.

Indeed, if and when Spitzer becomes governor, we’ll discover what his reformist zeal is really made of–and how far it will take him. By demonstrating both Spitzer’s ability and the astonishing success of his political formula, Masters’s exhaustive study shows that it would be unwise to place limits on our estimation of this unique public figure’s ambitions–or his ability to realize them.

Greg Sargent

Greg Sargent writes the Plum Line blog for the Washington Post. He covered Hillary Clinton’s Senate years for the New York Observer and New York magazine.