I recently got a call from a teacher at the University of Chicago Lab Schools who wanted to let me know just how many private school teachers detest the educational policies of Mayor Rahm Emanuel.

He caught me off guard, because I'd assumed that people at the school would espouse the get-tough-on-teachers mentality of Mayor Emanuel and his predecessor, Mayor Daley, since both mayors sent their kids there. Not to mention Arne Duncan, President Obama's education secretary, who went to Lab. Or, while we're at it, President Obama, whose kids also attended the school.

But no—it turns out that Lab has a progressive and tolerant attitude toward its teaching staff.

Look, I don't blame any of these parents for sending their kids to Lab. It's one of the highest-achieving schools in the country, in part because it attracts and keeps a dedicated band of outstanding teachers.

And one of the ways the school does it? "We have a pretty good contract," the Lab teacher tells me.

As in a contract with a union—local 2063 of the American Federation of Teachers. The AFT is the same national to which the Chicago Teachers Union belongs.

I think we should pause to appreciate the irony that Mayor Emanuel sends his children to a unionized private school while working overtime to break the public school teachers' union in Chicago.

The Lab contract protects teachers from some of the more—how do I put it?—wacky educational schemes of the Mayor Emanuel era.

For instance, Robert Zimmer, the president of the University of Chicago, would not be free to unilaterally order a change in curriculum at the Lab Schools—as Mayor Emanuel recently did when he imposed a "wall-to-wall" International Baccalaureate program at Lincoln Park, Taft, Hyde Park, and Senn high schools.

In that instance, Mayor Emanuel made a change without any evidence of having substantively studied just what the hell he was doing, which is pretty much the same thing he did with his longer-school-day ultimatum. He certainly didn't consult teachers, students, parents, or local school councils.

Many of them didn't know the wall-to-wall IB was coming until the mayoral press conference where Mayor Emanuel announced he was going to fix something that wasn't broken.

Anyway, President Zimmer wouldn't get away with that at Lab. On page six of the Lab teachers' contract, under the heading "Faculty Participation," is a stipulation that "the Administration recognizes the desirability and need for regular consultation with the faculty in areas of mutual interest."

And "the Administration and Faculty Association agree that there is an appropriate role for the faculty in the decision-making processes of the Laboratory Schools."

And "any modifications or changes of the processes shall be decided by appropriate administrative and faculty representatives."

The contract even goes on to stipulate that the administration can't change a teacher's classroom without notifying the teacher first.

Just so you know, Mayor Emanuel hasn't met with Karen Lewis, the president of the Chicago Teachers Union, since August 2011, when he told her to go fuck herself.

Sorry about the nasty language, but it tends to come up when I'm quoting your mayor.

Back to the Lab contract: there's no way President Zimmer would get away with yanking a book from the classroom of a Lab School teacher. I am of course referring to the infamous matter of Persepolisgate, when someone in Mayor Emanuel's central office mandated that the great coming-of-age graphic novel Persepolis be unceremoniously pulled from classrooms and libraries because . . .

Well, it's still not clear why they wanted to yank it, since the yankers offered no indication they had read the book or considered what it was about.

In any event, the teachers at Lab are protected from such intrusions thanks to the "Academic Freedom" clause of their contract, which reads: "Academic freedom shall mean that teachers are free to present instructional materials which are pertinent to the subject and level taught."

In CPS, academic freedom means Mayor Emanuel's free to do whatever he wants with the schools, including closing 54 of them.

Finally, there's the all-important matter of firing "bad" teachers, which in Chicago generally means anyone who doesn't worship the ground on which the principal walks.

In the last few years, CPS officials have adopted some very clever bureaucratic ruses to get around the contract with the teachers' union. In effect, CPS has abolished tenure for public school teachers.

For instance, Mayor Daley's educational aides invented something called "redefinition," which enables them to fire a teacher by "redefining" his or her position. Here's how it works: You redefine an English teacher's job to English teacher with a specialty in basket weaving. Then you tell the existing English teacher, "Sorry—you don't have the requisite qualifications to teach kids how to weave a basket while reading Beowulf. Don't let the door hit you on the way out."

Mayor Emanuel added his own twist by redefining entire schools—as with the wall-to-wall IB designations. That enabled the principal at Lincoln Park High to fire eight teachers in one swoop.

Mayor Daley must be watching enviously and wondering, "Dang, man, why didn't I think of that?"

Well, again, President Zimmer wouldn't be able to get away with that at the Lab Schools. For one, as I already mentioned, he can't unilaterally change curriculum without running it by the teachers. In addition, the Lab contract lays out a very specific procedure for getting rid of "bad" teachers: it includes classroom evaluations, peer review, remediation, and so forth.

He certainly wouldn't get away with firing a teacher for the high crime of putting forms that belong in the red notebook in the blue notebook, or whatever it was that science teacher Allison Bates did before her principal ran her out of the system. That's a story that should be required reading for anyone who even thinks about coming to Chicago to teach in the public schools.

Anything else? Oh yeah—the Lab contract guarantees that classes be capped at 24 kids. Unlike the Chicago Public Schools, where they'll cram 30 to 35 kids into a classroom if they can get away with it.

I'm sure the Lab teachers wouldn't even need to have the class-size rule in their contract, because parents would raise holy hell if President Zimmer tried to pack as many kids into one class as Mayor Emanuel wants to do with his latest round of closings and consolidations.

Well, you know what they say: class size doesn't matter as long as it's someone else's kid in the crowded classroom.

Finally, Lab pays its veteran teachers more than their public-school counterparts. The top end of the scale is about $104,000, about 10 percent more than in CPS.

In Mayor Emanuel's system, those would be the first people he'd have his principal fire. The less money he has to spend on teachers, the more he gets to spend on his cronies.