MICHAEL MULGREW is an affable former Brooklyn vocational-high-school teacher who took over last year as head of New York City’s United Federation of Teachers when his predecessor, Randi Weingarten, moved to Washington to run the national American Federation of Teachers. Over breakfast in March, we talked about a movement spreading across the country to hold public-school teachers accountable by compensating, promoting or even removing them according to the results they produce in class, as measured in part by student test scores. Mulgrew’s 165-page union contract takes the opposite approach. It not only specifies everything that teachers will do and will not do during a six-hour-57 ½-minute workday but also requires that teachers be paid based on how long they have been on the job. Once they’ve been teaching for three years and judged satisfactory in a process that invariably judges all but a few of them satisfactory, they are ensured lifetime tenure.

Next to Mulgrew was his press aide, Richard Riley. “Suppose you decide that Riley is lazy or incompetent,” I asked Mulgrew. “Should you be able to fire him?”

“He’s not a teacher,” Mulgrew responded. “And I need to be able to pick my own person for a job like that.” Then he grinned, adding: “I know where you’re going, but you don’t understand. Teachers are just different.”

That is the kind of story that makes Jon Schnur smile. Schnur, who runs a Manhattan-based school-reform group called New Leaders for New Schools, sits informally at the center of a network of self-styled reformers dedicated to overhauling public education in the United States. They have been building in strength and numbers over the last two decades and now seem to be planted everywhere that counts. They are working in key positions in school districts and charter-school networks, legislating in state capitals, staffing city halls and statehouses for reform-minded mayors and governors, writing papers for policy groups and dispensing grants from billion-dollar philanthropies like the Bill and Melinda Gates Foundation. Bill Gates, along with Education Secretary Arne Duncan; Teach for America’s founder, Wendy Kopp; and the New York City schools chancellor Joel Klein could be considered the patron saints of the network.

Over the last several months, Schnur and the well-positioned fellow travelers on his speed dial have seen the cause of their lives take center stage. Why the sudden shift from long-simmering wonk debate to political front burner? Because there is now a president who, when it comes to school reform, really does seem to be a new kind of Democrat — and because of a clever idea Schnur had last year to package what might otherwise have been just another federal grant program into a media-alluring, if cheesy-sounding, contest called Race to the Top. It has turned a relatively modest federal program (the $4.3 billion budget represents less than 1 percent of all federal, state and local education spending) into high-yield leverage that could end up overshadowing health care reform in its impact and that is already upending traditional Democratic Party politics. The activity set off by the contest has enabled Schnur’s network to press as never before its frontal challenge to the teachers’ unions: they argue that a country that spends more per pupil than any other but whose student performance ranks in the bottom third among developed nations isn’t failing its children for lack of resources but for lack of trained, motivated, accountable talent at the front of the class.

Schnur, who is 44, became interested in education when, as an editor of his high-school newspaper, he read a draft of an article from a student who had transferred from a Milwaukee public school to his school in the suburbs. “She was savvier than any of us on the editorial board, but the draft was just so terribly written,” he told me. Schnur added that “the more I got to know her, the more I became obsessed with why public education hadn’t reached people like her.” After graduating from Princeton, he worked in the Clinton campaign and then landed an education-policy job in the Clinton administration.

Schnur recalls that when he met Barack Obama before his Senate campaign in 2004, and heard him talk about education, “I figured this guy could be the great education president — in 2017.” When Obama moved up the timetable, Schnur joined his 2008 campaign as a policy adviser. Six months later, he was working as a counselor to Education Secretary Duncan. As the Obama administration prepared to spend $80 billion in education aid as part of the economic stimulus program, Duncan and Schnur diverted $4.3 billion to the contest aimed at encouraging cash-strapped states to overhaul their public schools. Schnur came up with the name and pushed the overall spin of the contest, and it was clear from conversations with people in the school-reform movement that he is the one person who seems to know everything happening on all fronts, from the White House to legislative chambers in Albany or Sacramento to charter schools in New Orleans. Joel Klein, for example, said he talks to Schnur about once a week.

The winners of the Race would be those states that submitted the best blueprints for fulfilling the reform agenda, which includes allowing school districts to take over failing schools, improving curriculum standards and encouraging school innovation (which means, in part, allowing charter schools to flourish). But what the reformers have come to believe matters most is good teachers. “It’s all about the talent,” Secretary Duncan told me. Thus, the highest number of points — 138 of the 500-point scale that Duncan and his staff created for the Race — would be awarded based on a commitment to eliminate what teachers’ union leaders consider the most important protections enjoyed by their members: seniority-based compensation and permanent job security. To win the contest, the states had to present new laws, contracts and data systems making teachers individually responsible for what their students achieve, and demonstrating, for example, that budget-forced teacher layoffs will be based on the quality of the teacher, not simply on seniority. (Fifteen states, including New York and California, now operate under union-backed state laws mandating that seniority, or “last in/first out,” determines layoffs. These quality-blind layoffs could force a new generation of teachers, like those recruited by Teach for America, out of classrooms in the coming months.) To enable teacher evaluations, another 47 points would be allocated based on the quality of a state’s “data systems” for tracking student performance in all grades — which is a euphemism for the kind of full-bore testing regime that makes many parents and children cringe but that the reformers argue is necessary for any serious attempt to track not only student progress but also teacher effectiveness.

By late March, when the first round of the Race ended, it was clear that Schnur’s spin had worked “better than any of us imagined,” he says. Thousands of local news stories across the country speculated about how particular states were faring, some of them breathlessly referring to the “March Madness” as governors, state legislators and bureaucrats rushed to consider reforms that might improve their chances. Forty states and the District of Columbia entered the first round. Fifteen, including such union strongholds as California, Ohio and Michigan, passed laws or revised regulations aimed at boosting their chances. Before Duncan had dispensed a nickel, the country had seen more school reform than it had in decades. And still more is being debated as the deadline for a second round of proposals looms next week and states, including New York, Connecticut and New Jersey, hustle to do more to boost their scores.

When the starting gun for the Race went off, four forces that had been building came together and gained strength from one another.

First there’s the rise of the reformers who seem to be in daily communication through e-mail and blogs. The standard profile is someone who went to a prestige college, joined Teach for America for a two-year stint and found the work and the challenges so compelling that he or she decided education should be more than a layover before a real career. So they did more teaching or became involved running a charter school or a reform group, then kept moving up the ladder as sympathetic political leaders, including Democrats (most in this network also seem to be Democrats), took over cities or states and looked for people to overhaul school systems. One exception is Schnur. “I was in Wendy’s class in Princeton in 1989, so I couldn’t do T.F.A. because it didn’t exist yet,” Schnur says, referring to Wendy Kopp, who founded Teach for America in 1990 based on a senior thesis she wrote envisioning a Peace Corps-like cadre of young college grads.

Although Schnur is a cheerful, modest type, there is a strain of self-righteousness that runs through the reform network. Some come off as snobs who assume any union teacher is lazy or incompetent and could be bested by young, nonunion Ivy Leaguers full of energy. And others see tying teachers’ pay to their students’ improvement on standardized tests as a cure-all. But most — especially those who have taught and appreciate how hard it is — understand that standardized tests are far from perfect, and that some subjects, like the arts, don’t lend themselves to standardized testing. They know that most teachers want to be effective and that data-based performance assessments should be combined with classroom observation and other subjective measures not only to hold teachers accountable but also to help them improve their performance.

The second force at work is a new crop of Democratic politicians across the country— including President Obama — who seem willing to challenge the teachers’ unions.

Third, there’s the boost given to school reform by high-powered foundations, like the Gates Foundation, which have financed important research and pilot reform projects, and by wealthy entrepreneurs, who have poured seed money into charter schools.

And fourth, there’s the charter-school movement, which has yielded an increasingly large and vocal constituency of parents whose children are among the more than 1.5 million students attending more than 5,000 charter schools.

Put those forces together with the Race, and you have education reform moving into prime time. Parents marched and lobbied in Tallahassee, Albany and Los Angeles, demanding that their school systems be reformed the way Obama’s instructions for winning the Race said they should. Newspaper editorial boards of all political stripes joined in their cause; “Union Lackeys” was a typical title of a Las Vegas Review-Journal editorial about recalcitrant Democratic legislators.

If unions are the Democratic Party’s base, then teachers’ unions are the base of the base. The two national teachers’ unions — the American Federation of Teachers and the larger National Education Association — together have more than 4.6 million members. That is roughly a quarter of all the union members in the country. Teachers are the best field troops in local elections. Ten percent of the delegates to the 2008 Democratic National Convention were teachers’ union members. In the last 30 years, the teachers’ unions have contributed nearly $57.4 million to federal campaigns, an amount that is about 30 percent higher than any single corporation or other union. And they have typically contributed many times more to state and local candidates. About 95 percent of it has gone to Democrats.

Before they successfully organized in the 1950s and 1960s, teachers endured meager salaries, political favoritism, tyrannical principals and sex discrimination against a mostly female work force. It’s that sense of needing to stick together against real or potential mistreatment by management, plus a sincere — and accurate — belief that most teachers do teach for reasons beyond simply making a living, that drives Mulgrew and other union leaders. There’s also the reality that their own power comes from making sure that the all-for-one-one-for-all contract that they negotiate remains the determining factor in a teacher’s professional life.