By Jonathan Zimmerman

In 2001, high school English teacher Shirley Evans-Marshall gave her class a copy of the American Library Association's "100 Most Frequently Challenged Books." She asked her students to choose a book on the list and explain why it was controversial.

But the assignment itself was too controversial for Evans-Marshall's Ohio school district, which declined to renew her contract.

Evans-Marshall sued, claiming a violation of her First Amendment rights. And last year, a federal appeals court ruled that she didn't have any - at least not in her own classroom.

"The right to free speech ... does not extend to the in-class curricular speech of teachers in primary and secondary schools," the court declared.

That's why teachers still need collective bargaining, which lies at the heart of this winter's bitter battles over public-employee unions.

But the plight of Evans-Marshall also speaks to the unique role of schoolteachers in a democracy.

Unlike the other workers that you see protesting outside of state capitols, teachers are charged with instructing young Americans about their responsibilities and rights as citizens. That won't happen if we hamstring teachers' own rights, by lumping them together with everybody else.

Yet that's precisely what our courts have done. The ruling in Shirley Evans-Marshall's case relied on the 2006 Supreme Court decision Garcetti v. Ceballos, which said that public workers have no First Amendment rights when they are speaking as part of their "official duties." The state hires the worker to deliver a message, the court said, so the state can also discipline employees who deviate from it.

He who pays the piper calls the tune.

That might be an appropriate rule for, say, a clerk at the motor vehicles administration. Not so for a teacher, who is enjoined to help young people learn how to reason, criticize, and debate. Teachers do not simply work for a democracy; they're supposed to teach it. And that requires a much greater degree of freedom than other public employees receive.

Alas, our courts have lost sight of the difference. So when Indiana teacher Jane Mayer told her class that she had honked her car horn in support of a rally against going to war in Iraq, her school district refused to rehire her. Invoking Garcetti, a federal appeals court ruled in 2007 that Mayer had no right to deviate from the school-approved curriculum.

"A teacher hired to lead a social-studies class can't use it as a platform for a revisionist perspective that Benedict Arnold wasn't really a traitor, when the approved program calls him one," the court declared.

But we should want our teachers to question whether Arnold was a traitor, and whether the war in Iraq is a good idea. And if the courts won't defend this freedom, then teachers will have to do it themselves.

That's where collective bargaining agreements come in. Historically, these agreements have protected teachers' salaries, benefits, and pensions. Now that the courts have gutted teachers' academic freedom, however, the only way they can retain it will be via collective bargaining.

But here, too, we're moving in the opposite direction. In Jane Mayer's native Indiana, the state Senate passed a measure last Tuesday that would limit teachers' negotiating rights to wages and benefits. In Shirley Evans-Marshall's Ohio, meanwhile, Republicans put forth a bill to end teachers' collective-bargaining rights altogether. Last Wednesday, they agreed to a revised proposal that would restrict teachers' bargaining to wages.

The fiercest battleground is still Wisconsin, where all the tumult began. Early Friday morning, its Assembly passed a bill that would bar collective bargaining by public workers on everything except - you guessed it - their wages. Now the focus shifts to the Senate, where Democrats have staged a walkout in order to avoid a vote on the measure.

One objective of these bills is to get workers to contribute more to their health and pension plans, by taking these plans off the negotiating table. The broader goal is to rein in the breadth and power of public-employee unions, which Republicans charge with putting too great a strain on state coffers.

They might be right. And like other public workers, teachers could reasonably decide to make some bread-and-butter concessions in these difficult economic times. But I hope they will never sign away their freedom in the classroom, or their right to bargain for it. A teacher cannot live by bread - or butter - alone. And neither can a democracy.

Jonathan Zimmerman teaches history at New York University and lives in Narberth. He is the author most recently of "Small Wonder: The Little Red Schoolhouse in History and Memory" (Yale University Press). He can be reached at jlzimm@aol.com.