On a warm night in June, filmmaker Davis Guggenheim premiered his latest documentary in front of a packed house at the Silverdocs Documentary Festival in Silver Spring, Maryland. Waiting for “Superman” rolls out in theaters this month; its subject matter–education reform–is a good fit for the season. Guggenheim chronicles the lives of a handful of schoolchildren scattered across the country who, like too many American students, are stuck in mediocre, even awful, schools. Life supplies the suspense: Guggenheim’s subjects are signed up for local charter-school lotteries, that new annual rite of hope and cruelty, in which parents desperate to help their kids have little recourse but to rely on bouncing balls or randomizing computers to gain admission into charters with limited spots.

Waiting for “Superman” aims to do for the burgeoning school reform movement what An Inconvenient Truth did for climate change: elevate a liberal activist cause to the top of the national agenda. This being the movies, it aims to popularize some new heroes in the public mind–advocates like Geoffrey Canada, president and CEO of Harlem Children’s Zone; Michelle Rhee, the D.C. public schools chancellor; and the KIPP schools, a charter management organization with more than 80 outposts throughout the United States. And where there are heroes, there are villains, and the movie anoints a new progressive bête noire: teachers’ unions.

After the screening, Guggenheim had a discussion with two of the film’s stars, Rhee, whose battles with the D.C. union have been well documented, and Randi Weingarten, head of the American Federation of Teachers. Here was an interesting moment. In a theater full of presumably good liberals (who else, after all, goes to see policy-reform documentaries?), the head of America’s second-largest teachers’ union was greeted with polite applause. Then, right behind her strode her nemesis, the union-taming Rhee–and the response was loud and enthusiastic.

For Weingarten, the scene must have been discomfiting, if not unfamiliar. Has any interest group taken as much of a beating as the teachers’ unions have in the past year? Last year, Steven Brill wrote a devastating piece in The New Yorker reporting on the now-infamous “rubber rooms,” where teachers accused of incompetence or wrongdoing would await their hearings, sometimes for years, while still collecting a paycheck and benefits from New York taxpayers, an emblem of union power run amok. (The city and union officials, embarrassed by the attention, closed the rooms in June.) Brill followed up with another piece in May in The New York Times Magazine, “The Teachers’ Unions’ Last Stand,” a headline that summed up the article’s grim take. Op-eds and editorials have gone on the attack as well, castigating unions for standing athwart reform yelling “Stop!” Meanwhile, Waiting for “Superman” isn’t even the only documentary bashing teachers’ unions to appear this year: Two other movies, The Lottery and The Cartel, beat Guggenheim to the punch a few months ago.

It’s not hard to see why the media and the movies have turned their attention to the teachers’ unions and the larger issue of education reform. In recent years, school reform has become the liberal cause du jour. New cohorts of elite-college graduates have made teaching a popular destination for the idealistic achiever. Teach for America, which recruits recent graduates to commit to teaching for two years in urban and rural schools, this year saw a record-breaking 46,000 applications for teaching slots across the country, accepting only a meager 12 percent. (Some of that bump can attributed to the poor economy, but there’s no disputing the program’s growing popularity.) Meanwhile, a new class of reformers has stepped forward and joined the achievement-gap battle, bringing fresh ideas with them: charter schools, merit pay, data-based performance assessments, expanded learning time, to name a few. As Kevin Huffman wrote in these pages last year, “There has never been a more innovative time in modern American education, particularly in high-poverty school districts.”

But the biggest factor in the rise of the reform movement is the arrival of a like-minded Democratic administration that has sought to harness and direct activist energies. President Obama’s data-driven, pragmatic brand of progressivism tracks closely with the reformist ethos, and his signature education initiative, Race to the Top, may well go down as one of his greatest accomplishments. The $4.3 billion program is classic Obama: Rather than a top-down law ordering school districts to change the way they do things, Race to the Top dangles the money in front of the states in a competition to see who can institute the most meaningful and far-reaching reforms. From Massachusetts to Tennessee to Colorado, states have pushed through reforms–more charters, greater power for superintendents, allowing longer school days–that unions have fought for years.

Thus do unions suddenly find themselves facing off against an Administration they had worked so hard to get elected. For years, teachers have been one of the most loyal constituencies in the Democratic fold. One out of every ten delegates at the 2008 Democratic National Convention was a teachers’ union member. But that relationship is now fraying. When the National Education Association (NEA), the nation’s largest teachers’ union, this summer held its annual convention, where Obama spoke two years in a row as a candidate and Education Secretary Arne Duncan spoke last year, the union didn’t invite a single representative from the Administration. The rhetoric that came out of the event couldn’t have been more bitter. “Today our members face the most anti-educator, anti-union, anti-student environment I have ever experienced,” said NEA President Dennis Van Roekel.

The unions have no one but themselves to blame. In recent years, stories of just how difficult it is to fire incompetent teachers have underscored the unions’ iron grip on our education system. There was the Connecticut teacher who received a mere 30-day suspension for helping students cheat on standardized tests; the Los Angeles teacher who told an eighth-grade student who survived a suicide attempt to “Carve deeper [into the wrists] next time,” and who managed to hang on to his job; the $400,000 in legal fees it cost New York taxpayers to fire a fifth-grade teacher so inept she failed to complete report cards. Just as objectionable has been the unions’ opposition to accountability standards, a posture that frequently takes the form of suspicion of data and measurement–a most un-progressive posture.

At the same time, it’s hard to ignore the fact that teachers’ unions are comprised of many idealistic people who went into education because of a genuine desire to help children. When an exasperated Weingarten vented that she constantly feels the need to break out her education bona fides these days–she taught history at a Brooklyn high school for several years–one could feel only sympathy for her. She may well have been speaking for millions of teachers who went into the profession with good intentions, and now find themselves vilified by the public.

The protracted breakup between the party and the unions is driven partly by the growing realization among progressives that the teachers’ unions have acted in deeply conservative ways. The primary objective of the teachers’ unions is to preserve their members’ hard-fought rights and benefits–as they should. Keep in mind that the advent of collective bargaining for teachers led to improvement in working conditions and higher pay for an underappreciated profession. Those battles won, unions now find themselves in the position of protecting what’s theirs. It’s a posture that has become inimical to the change reformers have been pushing. The reform movement has coalesced around teacher quality as the sine qua non of progress. As a study from the Economic Policy Institute, a progressive think tank, noted, “Teacher quality…is the most important school-related factor influencing student achievement.” But improving teacher quality means letting go of bad teachers. Teachers’ unions, unfortunately, don’t discriminate between good and bad teachers–the job protections they fight for are there for all of their members.

Writing in The Village Voice this summer, Nat Hentoff wrote of a backlash against teachers’ unions among black parents who see them as standing in the way of bringing better schools to the city. Bill Perkins, a state senator from Harlem and New York’s fiercest charter-school critic, is in the political fight of his life, and just might get bounced in this month’s Democratic primary by Basil Smikle, a political strategist and charter-school proponent. In his Times Magazine piece, Brill quoted one Harlem father as saying, “Someone like Perkins has to know that we know” the disparity in outcomes between the district’s charter and public schools–a reflection of the growing sentiment that teachers and their political allies are standing in the way of better schools.

But the reform movement is at its core an upper-middle-class–and mainly white–uprising, reminiscent of nothing so much as the turn-of-the-twentieth century Progressive Era activists: educated, urban, broadly reformist. What’s more, it’s a movement with deep pockets. George Mowry once wrote of the Progressives, “few reform movements in American history have had the support of more wealthy men.” The depiction fits the education reform movement, swimming in foundation money (the Gates Foundation and the Walton Foundation, to name two) and studded with wealthy donors.

So it is that the cosmopolitan progressives who until recently stood with the unions on the ramparts of liberalism are now leading the charge against them. Guggenheim exemplifies the new breed: Here’s the director of An Inconvenient Truth and Obama’s 30-minute campaign infomercial, son of the filmmaker who made a legendary film of Robert F. Kennedy that aired at the 1968 convention, making a documentary whose take on the unions could have come out of an American Enterprise Institute paper. Waiting for “Superman” opens with footage of Guggenheim driving past three public schools to drop his kids off at their private school, a choice that he acknowledges was wrenching for a progressive like him. It’s the act of a liberal mugged by the public school system, and it reflects an increasingly common experience. As the liberals who have been supportive of unions began having their own kids in urban districts, they came face to face with the grim fact of our schools–and unions that seemed to care more for their own interests than their children’s. Today’s cosmopolitan progressives more than likely grew up in middle-class homes with salaried, professional parents. That white-collar insulation from the world of wage-worker labor, as C. Wright Mills once surmised, could also explain their apathy for unionism. The choice between labor and their own kids was no choice at all.

There is no denying that the rise of the reformers has been, on balance, a good thing for American education. Many smart people have suddenly made the improvement of our schools their life’s work. Though charter schools have not produced uniformly stellar results–and some have performed miserably–there have been notable success stories. A study by the National Bureau of Economic Research found that KIPP students in Lynn, Massachusetts, showed proficiency gains in English and math compared to Lynn students who sought to attend KIPP but did not get in. Another school, the Harlem Success Academy in New York, has shown marked strides in student achievement for less money per student compared to the public school next door. More data are needed, of course, but we should learn to recognize–and scale up–success where it occurs.

State lawmakers, long beholden to the unions and their largesse, have in the last couple of years enacted reforms that were unthinkable a decade ago. And unions, responding to the pressure, are showing signs of evolving. In D.C., the union recently agreed to a new contract that gave Rhee greater power to dismiss underperforming teachers and reward excellent ones. For unions, evolution is the only logical move. They can vent at conventions all they want, but the plain fact is that they have nowhere else to go. The Administration might spurn them, Democratic leaders might score them, reform advocates might disdain them–but conservatives don’t even want them to exist.

For all the good that the reform movement has accomplished, there is nonetheless something unseemly about the cheerleading and bandwagon-jumping. There is a danger in pinning your hopes for reform on charismatic personalities rather than a sustainable movement. And with each new magazine cover and talking-head appearance–think of the Rhee media juggernaut of the last couple of years–reform’s representatives threaten to become bigger than the movement they lead. Klieg lights have a way of turning the people in front of them into performers. The worst thing that can happen to the cause of school reform in this country would be for it to become a personality-driven movement. (Some might even ask if it’s not already there.)

But more alarming than the idolatry is the piling on. Progressives have turned against labor with gusto. Reporting from an education event around the time of the 2008 Democratic convention, the journalist Dana Goldstein found a line-up of big-name Democrats–D.C. Mayor Adrian Fenty, Newark Mayor Cory Booker, former Colorado Governor Roy Romer–fulminating against unions in front of an approving audience of fellow party members. The same dynamic played out that June night in Silver Spring, as Rhee’s red meat about unions was devoured by the reform-minded crowd. It was a congregation that had had enough of unions, and that saw “change agents”–that new term of art–like Rhee and Canada as the true champions of progressive goals. (More recently, mayors and governors, Democratic and Republican, have trained their fire on other public-sector unions, whose members they see as milking taxpayers for generous benefits in these impecunious times. This theater of war will only expand in the coming months.)

The tarring and feathering of unions by progressives prompts serious questions about the nature and direction of progressivism. After all, unions have been essential to the achievement of progressive goals. The health-care reform bill would likely not have passed without labor muscle. (It’s worth noting that the unions’ valiant effort came despite the concessions they made, and how little the Administration has done for them to date.) On a more fundamental level, unions remain liberalism’s primary bulwark against corporate power, and the working class’ strongest advocate at the bargaining table. Though teachers’ unions have undoubtedly stood in the way of innovation in the education sector, they also remain the most obvious partner for enduring reform, particularly if the current wave of advocacy proves short-lived–a brief flash of agitation before the money and the minds move on to the next new cause.

Part of the new liberal attitude toward unions can be chalked up to complacency–we know they have nowhere else to go come election time. But what is liberalism without unionism? Can a lasting progressive movement be built on a foundation of anti-union reform? When conservatives take power again and seek to roll back our gains, will progressives want unions back on the ramparts with them–and will unions be so weak from our bashing, so disreputable from our demonizing, to be of little help by then? These are difficult questions. From the looks of things, few progressives have even thought about asking them.