New York

Teachers unions are on the defensive these days. The Obama administration is pushing various measures long opposed by the unions: charter school expansion, pay-for-performance, teacher evaluations and more. States and localities are looking to change collective-bargaining rules and scale back costly, bloated education work forces that have grown even when student enrollment was flat or declining. And Hollywood, in recent documentary films like “Waiting for ‘Superman,'” “The Lottery” and “The Cartel,” has highlighted how teachers unions block or stifle education reforms to the detriment of the low-income minority kids who populate the nation’s worst schools.

When I sit down for an interview with Randi Weingarten, who has been head of the American Federation of Teachers since 2008, my first question is whether those films are getting her recognized more in public these days.

“Actually, no,” she responds, not particularly amused by the query. “I’m used to the use of scapegoating and demonization and finger-pointing as a mechanism to divert or distract from problem-solving.”

“We want to improve public schools,” says Ms. Weingarten. “Ninety percent of the kids in the United States of America go to public schools, and it’s our responsibility to help them. I think every single child deserves a great education.” These films, she said, “are all made by people who have not ever once looked at a good public school.” She adds that what bothers her in particular about “Waiting for ‘Superman'” is that “there was not one public school teacher in a unionized setting who was acknowledged as a great teacher, and there are hundreds of thousands of them. . . . So you have a movie like ‘Waiting for “Superman,”‘ which is about one [charter] school, when so many other charter schools don’t do a good job.”

In fact, “Waiting for ‘Superman'” tracks five children who enter lotteries at four charter schools located in two states and the District of Columbia. It explicitly notes that not all charter schools are high-performing. And it features footage of the late Harriett Ball, the influential public school teacher in Houston who mentored Dave Levin and Mike Feinberg, the two young teachers who would co-found KIPP, the most successful charter school network in the country.

I ask Ms. Weingarten about union-backed laws in 14 states mandating that teachers be laid off by seniority instead of job performance, and whether they help improve public schools. Why can’t teachers who have been chronically absent from work be the first to go? Or the ones who have been convicted of crimes? Or the ones who are languishing—with full pay and benefits—in some “reserve pool” because no school will hire them? Education Secretary Arne Duncan recently said that “last in, first out” policies hit low-income kids hardest because the poor are more likely to attend schools where teachers have less seniority.

Says Ms. Weingarten: “It’s not the perfect mechanism but it’s the best mechanism we have. You have cronyism and corruption and discrimination issues. We’re saying let’s do things the right way. We don’t want to see people getting laid off based on who they know instead of what they know. We don’t want to see people get laid off based on how much they cost.” She praises New York Gov. Andrew Cuomo for defending the state’s seniority system.

What about teacher-tenure rules that offer lifetime sinecures after two or three years in the classroom and compel principals to hire bad instructors? “If you eliminated due process, what we would get is we would lose innovation and risk-taking in schools,” she says.

And so it goes. Ms. Weingarten insists that teachers unions are agents of change, not defenders of the status quo. But in the next breath she shoots down suggestions for changes—vouchers, charter schools, differential teacher pay and so on—that have become important parts of the reform conversation. She seems to conceive of her job as the one William F. Buckley Jr. ascribed to conservatives in the 1950s: To stand athwart history yelling “Stop!”

“We’ve started some charter schools, but there are studies out there that say 80% of charter schools are no better [than traditional public schools] and 37% are worse.” she says. “We’ve tried merit pay in a few places [but] there’s a new study from Vanderbilt University that says it doesn’t work.” And school vouchers “have never been shown to be successful,” she insists, ignoring the results of a study last year by Patrick Wolf of the University of Arkansas, who found that “students in Washington, D.C., who used a federally funded voucher to attend a private school were more likely to graduate from high school.”

Ms. Weingarten is dismissive of some of the country’s leading public education reformers. Michelle Rhee, the celebrated former schools chancellor in Washington, D.C., who negotiated a teachers contract that has become a nationwide model, “had a record that is actually no better than the previous two chancellors.” And Joel Klein, the former education chief in New York City who closed 91 failing schools and sought to change the process for awarding tenure, is a reformer-come-lately who “just started talking about revamping teacher evaluations this past Sunday.”

The labor leader downplays differences with the Obama administration, despite its tough talk on holding teachers more accountable. “We’ve been generally supportive of what the president and the secretary of education have done,” she says. So either her union doesn’t take the rhetoric seriously, or Team Obama can say whatever it wants so long as the education spending spigot remains open.

Then there’s the matter of collective bargaining for public workers, which has caused so much controversy in Wisconsin and elsewhere—and which past labor leaders resisted. Former AFL-CIO President George Meany, for example, said that “it is impossible to bargain collectively with the government.” And Franklin Roosevelt said that “all government employees should realize that the process of collective bargaining cannot be transplanted into the public service” because “it has distinct and insurmountable limitations when applied to public personnel management.”

“If Meany and FDR were alive today, they’d have a very different view,” Ms. Weingarten says.

“What’s happening now is you see George Meany’s successors, Richard Trumka and others—you see FDR’s successors as governor of New York—all giving people collective-bargaining rights. What collective bargaining does in the public sphere is that it helps transform systems. It helps focus on equality. It helps create a check and balance that’s really important.”

The AFT and its larger sister organization, the National Education Association, may be the most powerful labor unions in the country. They have a combined membership of more that 4.5 million, and their policy influence reaches far beyond public schools. Political donations from these groups go overwhelmingly to Democrats, and the role that member dues play in the wider liberal movement can be seen in teachers union support for everything from abortion rights to single-payer health care to statehood for Washington, D.C.

But the real strength of the AFT, NEA and their state and local affiliates lies in their ability to obstruct. They have been particularly effective at blocking poor people from leaving bad public schools. They offer financial and logistical support to political candidates sympathetic to their agenda of curbing educational options, and they punish elected officials who don’t stay the course.

Teachers unions agitate for laws and regulations that ban means-tested voucher programs or cap the number of charter schools that can open in a state. To protect jobs for their members, they fight to keep the worst instructors from being fired and the worst schools from closing. All the while, they insist that their interests are aligned with those of the kids.

It is this skill set that has made Ms. Weingarten a documentary film star. And it is why education reformers, of all political stripes, focus so much of their attention on undermining the teachers unions and setting up public charter schools that can operate outside of their grip.

Mr. Riley is a member of The Journal’s editorial board.