In the spring of 2007, I moved to New York City to cover what I was sure was the most important story in the country. One of those annoying people who had settled on a career before I knew how to drive, I was a young and enthusiastic reporter on the education beat. In New York, I could cover the biggest education revolution ever attempted: a total overhaul of the way public schools worked, in the country’s largest school system.

The drivers of this transformation were the city’s billionaire mayor, Michael Bloomberg, and his handpicked schools chancellor, Joel Klein, a prosecutor who had previously taken on Microsoft and had now set his sights on toppling his hometown’s education status quo. “BloomKlein,” as their enemies called them, radiated a crusading moral confidence. Both liked to say that their work, begun in 2003, was the next phase of the civil-rights movement. And they wielded unprecedented authority to actually follow through on their enlightened mission to tackle inequities and eradicate dysfunction; in 2002, state lawmakers had dissolved New York City’s elected school board and handed total control to the mayor. Supporters and opponents alike shared the BloomKlein conviction that their “disruptions” would soon spread to cities all across the country.

It was june 2007, and I was following the mayor around as he took a victory lap celebrating record-high test scores. “Who’s excited about summer?,” Bloomberg asked a group of 5-, 6-, and 7-year-olds seated in front of him at their new Harlem elementary school, which had opened the previous August. He ticked off the fun things they might do once school let out, like go to the pool. The school’s principal, Eva Moskowitz, spoke next. She didn’t “want to contradict the mayor,” she said solemnly, “but there’s going to be some swimming, but there’s also going to be some reading.” Later, the mom of a kindergartner told me just how serious the principal was. To keep up with the school’s reading requirements, she and her son regularly hauled 50 books home from the library. What were you doing in kindergarten?

I had visited impressive schools before, but none quite like this one. The kids, who congregated in a corner of a large public-school building on West 118th Street, were a sight with their orange-and-blue uniforms and blue backpacks. But the person who made the biggest impression was Moskowitz herself. She stalked the school corridors more like a rear admiral than a pedagogue, rattling off to whomever would listen the obstacles she was up against: union rules governing sink repair, school bells ringing on a cryptic schedule, doors requiring custom fixes. She was either paranoid or plagued, probably some of both. Feeling under siege, she could either defend or attack. She picked the Napoleon option.

Like other charter schools—which operate independently of a school district’s control but are still publicly regulated and funded—Harlem Success Academy, as the school had been named, was starting up slowly, serving 165 kindergartners and first-graders in its inaugural year. But already Moskowitz had set herself apart. While other charter-school leaders ran only a handful of schools in a given state, she planned to open 40 more schools like this one. All in New York City, and all in a single decade.

I underlined the number in my reporter’s notebook. By some measures, 40 wasn’t unprecedented. The country’s best-known charter network,kipp, had grown to 46 schools by 2006. It was part of an expansion funded by the founders of the Gap, Doris and Don Fisher, after the charter movement took off in the 1990s. But kipp schools were spread across 15 states, with just a few schools per city. New York City had four. Like the Gap, which had made its name targeting young people, the point was to serve not an entire market, but a niche—in kipp’s case, the poorest students.

Forty Success Academy schools in a single city in a decade, on the other hand—that was two-thirds the number of charter schools in all of New York City at that point. What Moskowitz had in mind was not a proof point but a blueprint, not a Gap but a kind of educational superstore. A whole new school system, run by her instead of the government. “Hopefully this will be the first prototype,” the chair of Harlem Success Academy’s board told me that day in 2007. “This is meant to be replicable.” I tried to picture 15,000 students across New York City, all carrying matching blue backpacks. Moskowitz couldn’t have stunned me more had she said that she intended to one day run for mayor (a goal she announced a few months later). Her charter plan was audacious, but it probably wouldn’t happen.

It happened, and then some. One school became 46. One hundred sixty-five students became 15,500. A tiny outpost in Harlem spawned brethren all across Manhattan, the Bronx, Brooklyn, and Queens; Harlem Success Academy is now part of the Success Academy Charter Schools network, of which Moskowitz—the author of a lively new memoir, The Education of Eva Moskowitz—is CEO. From that position, she has become one of the country’s most influential crusaders at a turning point for charter schooling.

Empire has not killed quality. On the contrary, students at Success—where intensive test prep in math and reading goes hand in hand with a strong emphasis on science, art, and chess—regularly trounce their peers all across New York on state tests. Unlike other high-scoring charter schools, such as kipp, Success saw no dip in performance after the state adopted the tougher Common Core academic standards. The stellar scores helped Moskowitz open more schools, faster, than any other charter-school leader in New York.

In her march forward, Moskowitz has added considerably to the ranks of her foes. Teachers who oppose charter schools carry signs denouncing evil moskowitz. In 2013, Mayor Bill de Blasio campaigned on an education platform of ending Moskowitz’s “run of the place.” Even many supporters hold Moskowitz at what can generously be called a careful distance, and I get it. Her acid tirades are legendary and can get scathingly personal more quickly than I might have believed had she not once dressed me down after I wrote a story she didn’t like.

The Education of Eva Moskowitz is plainly positioned to soften and humanize, yet even here, she often swerves into score-settling eviscerations of her perceived enemies. She devotes two chapters to decrying the media, in particular a New York Times reporter’s coverage of Success’s disciplinary practices; Moskowitz accuses her of a biased “abuse” of journalistic privilege. Lazy, meanwhile, is a tag she affixes to students and bureaucrats alike. She has no patience for critics who question Success’s high-stress test prep (as some of her own teachers do). Nor can she resist deriding fellow charter-school leaders as “political pacifists.”

How big should Success get? She doesn’t specify, but says that “maybe a public school system consisting principally of charter schools would be an improvement.” A proud product of public schools herself, Moskowitz did not reach this conclusion lightly. Imagining the end of public education as we know it—or at least its significant diminution—at first felt “almost disloyal,” she writes. But that was before she lost faith in schools run by the government. In her memoir she describes how she finally decided against a mayoral run—swayed not by a lack of ambition but by a surplus of it. The point is worth pausing over: Moskowitz has realized that she can do more to change public schools as a private citizen than as mayor—by operating outside of democracy rather than within it. I agree with her, and that unsettles me.

Moskowitz came by her disillusion firsthand. In 1999, then in her 30s, she ran for New York’s city council, spurred in part by a desire to improve the city’s schools. She’d lived through hapless management (in high school, she never used the bathroom, because the stalls had no doors) and wildly uneven teaching quality (one teacher at her high school slept through class drunk, she reports). She won the race and, investigating what held back the schools, found a chief culprit: constrictive union contracts fortified by labor’s monopoly over local politics. She set out to use her city-council seat to publicize the unions’ power and create living proof of an elected official who flouted the unions and lived to tell the tale.

In a dramatic series of hearings she held in 2003, one set of witnesses described the rules governing how school custodians were paid—not according to how well they maintained the building, but according to how little of the school’s custodial budget they spent doing so. Leftover funds became bonuses, arguably disincentivizing the provision of, say, doors on bathroom stalls. “As political theater, it doesn’t get much more dramatic than this,” the New York Observer wrote.

As actual politics, Moskowitz’s attempt to prove that a politician could survive taking on organized labor backfired. In 2005, she lost a close race for the next rung of office, Manhattan borough president. In the months that followed, Joel Klein approached elected officials for support of his reforms, which had also earned the ire of the teachers’ union. Over and over, he received the same rueful rebuff: “I agree with you, but I ain’t gonna get Eva’d.” When the time came to negotiate a new contract with the teachers, just before Bloomberg’s 2005 reelection campaign, even the mayor—seemingly protected from politics as usual by his personal fortune—succumbed to union pressure, according to Moskowitz and others. Klein ended up having to accept a contract he didn’t like. By then, plans for Moskowitz’s first charter school were under way. She was ready to test the viability of working outside the government.

I also knew that we Americans have good reasons for subjecting our public schools to the direction of elected government. We like democracy, especially when it gives us a say in what and how our children are taught. Unwieldy though school districts may be when they’re run by a school board or a mayor—and guided by the dictates of governors, state lawmakers, Congress, and the president—they give citizens a chance to weigh in. They are without a doubt public.

And yet, as I began work in 2010 on a book about teaching, I started to see why blowing up school districts might not be as crazy an idea as I initially thought. What struck me most is how impossible teaching is, especially in traditional public schools. While those who pursue the profession in other countries are provided with the infrastructure crucial to educating kids effectively—a clear sense of what students need to learn, the basic materials necessary to help them learn it (such as a curriculum), and a decent training system—teachers in the U.S. are left stranded.

The reason isn’t terrible union contracts or awful management decisions. The fault, I came to see, lies in the (often competing) edicts issued by municipal, state, and federal authorities, which add up to chaos for the teachers who actually have to implement them. It’s not uncommon for a teacher to start the year focused on one goal—say, improving students’ writing—only to be told mid-year that writing is no longer a priority, as happened just the other day at a Boston school I know of. We could hardly have designed a worse system for supporting good teaching had we tried.

Of all the reforms that have set out to free schools from this trap, to date I’ve seen only one that works: the implementation of charter-school networks. Large enough to provide shared resources for teachers, yet insulated from bureaucratic and political crosscurrents by their independent status, these networks are creating the closest thing our country has ever seen to a rational, high-functioning school system. They have strengthened public education by extracting it from democracy as we know it—and we shouldn’t be surprised, because democracy as we know it is the problem.

The network approach is gaining traction. Although charter schools are still boutique side offerings in most parts of the country, a growing number of cities have turned them into a centerpiece, which makes The Education of Eva Moskowitz especially timely and important reading. (Last November, the president-elect paraded Moskowitz into Trump Tower during his auditions for secretary of education; after she took herself out of the running, he selected Betsy DeVos.) Today, charter schools educate 94 percent of students in one city, New Orleans, and more than 30 percent of students in 19 other cities. If a determined group of philanthropists have their way, charters will take a leading role in more cities soon. Many of these schools are part of ambitious and fast-growing networks like Success.

In New York City, for instance, nearly 2 percent of all public-school students currently attend Success Academies, a percentage bound to climb. When I spoke with her recently, Moskowitz told me that she expects her network to expand to 100 schools in the next decade. That means Success would serve more than 50,000 students, making the network roughly the same size as Syracuse’s and Buffalo’s school districts combined. In Denver, meanwhile, a charter-school network called DSST Public Schools—which, like Success, has regularly posted academic results well above average public-school scores—will educate nearly a quarter of all middle- and high-school students in the city in the next decade. In New Orleans, four large charter networks together enroll one-third of all students who attend public school.

If the trend continues, parents across the income spectrum won’t face a tapestry of alternatives to the mainstream school district, each one with its own name and unique approach. Instead, they will get to choose from a handful of charter-school networks that are likely to make the original district—the one governed by an elected school board or the mayor, depending on the city—more peripheral.

Another new book, Reinventing America’s Schools, by David Osborne of the Progressive Policy Institute, describes the spread of charter schools as the shedding of an antiquated bureaucratic skin. He uses a nautical metaphor to illustrate the distinctive way charter schools work. At traditional public schools, the various layers of government are responsible for both steering and rowing. They steer by supplying funding and deciding what schools should broadly aim for: what kids should learn, and by when. The government also rows, hiring the bureaucrats and superintendents and teachers charged with meeting those goals. In the charter-school model, government responsibility ends at steering—providing funding, deciding which measures of success matter, and holding schools accountable for results. Choosing whom to hire (and fire), what to pay them, what else to spend money on, how to design curricula—all those decisions are contracted out to private, mostly nonprofit organizations. Those are in turn governed by boards usually—in the case of larger networks like Success—made up of wealthy donors.

Almost everything you’ve heard that’s great or terrible about charter schools flows from these two big changes. Because of the difference in governance, charter-school teachers are less likely to be represented by unions. Thus, depending on whom you talk to, charters are either union-busters or mercifully free from union strictures that put teachers before students. Disciplinary policies also reflect charter schools’ monopoly on rowing. Traditional public schools must follow suspension and expulsion policies written by the school district; charter schools write their own rules, and many have a no-excuses style that mandates good posture, precisely folded arms and legs, and silent hallways—injunctions some hail as essential to a strong school culture and others skewer as paternalistic and inhumane.

The lottery innovation—also known as “school choice”—invites perhaps the most-polarized interpretations. A district can allow one of its schools to expel a student, but it still bears responsibility for making sure he is educated somewhere else. Similarly, a district has to educate every child in its purview, whether she started in kindergarten or arrived yesterday from Jamaica, and no matter how far behind she may be academically. Many charter schools, by contrast, admit students only during the once-a-year lottery, and sometimes only in certain grades. But while critics see the lottery approach as an abdication of responsibility, Moskowitz and Osborne champion it as a tool for social justice. Neighborhood schools, they argue, institutionalize housing segregation, making a child’s zip code his educational destiny. Charter schools, by contrast, hand the power of choice to parents who can’t afford to exercise it through real estate.

What do we lose if and when public education takes this new shape? Supporters of a charterized public-school system argue that we’ll be giving up only on a fantasy, a “theoretical ideal,” in Moskowitz’s words. We like to think that our current public-school system is democratic. In reality, voter turnout for school-board elections—the main mechanism for holding schools accountable to local communities—averages between 5 and 10 percent. We dream that public schools serve all children equally well, whatever their background, race, or level of need. The reality is not even close. Many of the policies that charter schools get criticized for, moreover, are rampant in traditional public-school systems. School districts adopted “zero tolerance” discipline before charters embraced the no-excuses approach. School districts, not charters, were the original architects of a system that divides students by race, class, and special needs and abilities. And the zones that create the beloved institution of the neighborhood school are notoriously impermeable to integration.

Moskowitz, meanwhile, has been advocating weighted lotteries that give preference to students from particular disadvantaged backgrounds, such as students whose first language isn’t English. And in Denver and Washington, D.C., the dizzying, M. C. Escher–esque system of a different lottery for every individual charter school—so complicated that only the savviest families with plenty of time on their hands could be expected to successfully navigate it—has been replaced by a more accessible single lottery. Worries about a lack of democracy could similarly be quieted by giving locally elected leaders more oversight of charters, an approach that reformers have adopted in Indianapolis and will try in New Orleans next year.

I want to believe in such an evolution. It would be the best of all worlds if the most efficient way to run great schools was also the most equitable, accountable, and parent-friendly. But I worry that’s hard to pull off. One problem is the lottery. Charter-school supporters say that nothing could be more liberating for parents than to grant them a direct say in which schools their children attend. But existing systems of parent choice compel a more skeptical view of the path to inclusion. A recent study of New York City’s public-high-school system—in which students have applied to schools outside their neighborhood for years—found that parents seem to care less about the quality of the school than about the academic ability of the other students there. Left to their own choices, parents could very well resegregate schools as effectively as zip-code-based systems of assigning schools have done.

Another problem is incentives. As Moskowitz built Success, she enforced what she calls a “dual mission”: first, to build schools “to which any parent would want to send their children,” and second, to enlist staff, students, and families in the fight for laws and policies that let Success build such schools. Her contention is that one mission reinforces the other. But does she wishfully overlook deeper tensions? For all Moskowitz’s eloquence about the importance of rigorous academics and extracurricular activities, teacher after teacher has reported that at Success, test prep always comes first, narrowing the kind of work students do. Similarly, however much Moskowitz aspires to make Success Academy inclusive, in practice she and her staff sometimes tell families to look elsewhere for a school, because Success just isn’t the right fit.

According to Moskowitz, the choices she’s made have been pedagogically driven. Opting out of backfilling ensures that her students aren’t distracted by peers who lag behind; test prep arms her students for the meritocratic ordeal ahead. At the same time, these policies clearly advance Success’s reputation and help cement its political power. If those imperatives sometimes entail putting the network’s organizational interests ahead of the broader well-being of students—both those inside Success schools and those who are kept out—the pragmatic trade-offs shouldn’t be glossed over.

Who gets to make these trade-offs? In large part, the decisions belong to Moskowitz—or, more accurately, to the Success board. Charter boards, designed to sidestep the unwieldy directives of democratic school governance and focus ruthlessly on leading good schools, are the main reason charter networks operate so well—and also the main reason I worry as the networks grow. Back in 2007, when I visited Harlem Success Academy, two men were also in the room with Moskowitz, the mayor, the kindergartners and first-graders, and their parents. In dark-gray suits, they stood silently at the back of the auditorium, arms crossed—present, but not intrusive.

Their names, I learned, were Joel Greenblatt and John Petry, and they were the hedge-fund managers who, as founders and board members of Harlem Success Academy, had recruited Moskowitz as their CEO. They were, I also learned, very nice gazillionaires. Petry, who graduated from the same Maryland public-school district I did, helped throw me a book party in 2014. To this day, he and his wife send their own children to Success schools. In the decade after my Harlem visit, he always cheerfully took my calls, though “Ask Eva” was the refrain when it came to on-the-record comments.

Yet Petry and Greenblatt aren’t just nice. They are in charge, and nobody elected them. Like Moskowitz, the two men who founded her school really want, I think, better schools for all kids, and I believe they want to achieve this by the most-ethical means possible. But as the three of them have worked at revamping and expanding the network’s slice of public education, they have added new members to its board, and predictably, they have picked some of the wealthiest and most politically connected people.

I don’t mean to suggest that Loeb and his counterparts in Denver, New Orleans, and beyond have nefarious motives. Unscrupulous school impresarios do of course exist, but they gravitate to the minority of charters that are for-profit, rather than to nonprofits like Success. But I do think that bequeathing power over the education of America’s children to a tiny group of ever more influential plutocrats means that the rest of us will have much less say in the direction of public schools than we do today.

As these networks grow, overseeing them will become both more important and more difficult. Already networks in several states have rejected requests for documents, saying that public-records laws don’t apply to them. Once the Success empire includes 100, 200, or even 300 schools, will regulators feel comfortable exerting their ultimate authority to shut a school down? Or will charter networks become, like banks, too big to change?

We can’t know for sure. We can speculate, though, and when I do, I worry. The best-case scenario is that the bigger Moskowitz’s network becomes, the more responsibility she and her board take—not just for their students and for their network’s growth, but for all students and the civic community, too. But what if well-heeled activists like Loeb decide to push for state laws that weaken regulators’ power and strengthen the power of wealthy board members (and why wouldn’t they)? The best we can do is hope that the same dogmatic confidence that has fueled the most promising model we have for public education won’t also destroy it.

This article was published in partnership with Chalkbeat, a nonprofit news organization covering education. It appears in the January/February 2018 print edition with the headline “The Charter-School Revolutionary.”