“We in America…generally put our faith in the ingenuity of the market — entrepreneurs and innovators — to erode barriers to entry and protect consumer welfare. But if monopoly power, once had, can be used to protect and extend itself, our reliance on the market will be frustrated and consumers will be hurt.”

That homily to the powers of competition is from a speech given more than two years ago by the prosecutor of Microsoft, Joel Klein, at the Haas School of Business at the University of California at Berkeley. We keep thinking of the sentiment as we watch the ambitious school reform initiative of Mr. Klein and Mayor Bloomberg, Children First, come under fundamental attack in the Assembly and the courts, and from the United Federation of Teachers.

It was only a year ago that things seemed so different. Mr. Bloomberg was fighting the state Legislature for control of New York City’s school system. Give me control, he said, and then hold me accountable. But almost from the moment the mayor regained the power over the city’s schools that Mayor Lindsay lost in the 1960s after the Ocean-Hill Brownsville debacle, the hopes for reform began to wane.

For our part, the trouble began when it became apparent that neither the new chancellor nor the mayor was going to embrace the idea of parental choice as a central element of the drive for reform. Mr. Klein has called vouchers a “sadly mistaken hypothesis,” and the mayor has suggested he sees the utility of vouchers as only marginal in the fight to get the vast numbers of pupils in New York a better education.

By failing to signal that they are prepared to challenge the education trust with an alternative, competitive system — or at least with the idea of choice — Messrs. Bloomberg and Klein have left themselves exposed to the harassing tactics, political blackmail, and legal shenanigans that are now bedeviling them.

The Bloomberg-Klein plan is hardly a revolutionary one, consisting primarily of the establishment of uniform reading and math curricula and a reorganization of the existing 32 school districts into 10 regions, yet the sheer variety of opposition to it is something at which to marvel. Advocates of mayoral control and even school vouchers, such as Sol Stern at the Manhattan Institute, and the president of the UFT, Randi Weingarten, find themselves at least nominally on the same side, opposing large parts of Children First. The state legislators who gave the mayor the authority he sought over the schools, such as Assemblyman Steve Sanders of Manhattan, chairman of that body’s education committee, are now fighting the mayor in court over the restructuring half of his plan.

The racial discrimination suit by the teachers is the most egregious of the attacks on the reform effort, though it is no doubt but a precursor of how the union is going to up the ante in its effort to put its members — not children — first. Such shenanigans, it seems, are what any reform effort that works within the monopoly system is bound to come up against. Plenty of people are vested in the status quo, and they will fight to protect their interests.

Take a Queens state senator, Frank Padavan, who supported the mayoral con trol deal but is now promoting legislation to thwart it; he’s worried about homeowners in his district that bought into high-perform ing District 26, which the mayor’s plan would merge with troubled Queens schools such as those in Jamaica. Or take Ms. Weingarten, who for her part likely only went along with mayoral control because she needed to deliver something to her members; after three botched mayoral endorsements in a row in 2001 — Alan Hevesi, Fernando Ferrer, and Mark Green — she made up with a 16% boost in pay. With that deal done, and a new contract coming up, it’s time for the UFT to play hardball, which could mean at least the threat of the union asking Albany to reverse last year’s control deal.

The tragedy for Messrs. Bloomberg and Klein is that by abjuring vouchers and a bold charter school effort at the outset of their reforms, they have permitted themselves to be maneuvered into this kind of game. All the more tragic because Mr. Klein spurred hope in many of us that the mayor’s decision to hire a celebrated trustbuster meant that he understood the conceptual nature of the problem.

We say “had hoped,” but in fact we still hold out hope. Mr. Klein is both brilliant and committed. He still has a golden opportunity to bring his trustbusting skills to bear on the real problem, that of monopoly: a monopoly of tax dollars, a monopoly of schools, a monopoly of teachers and their union dues, a monopoly of political power, and a plethora of other monopolies, all tied together in the Department of Education’s new headquarters, the Tweed Courthouse. Many are watching as Washington, D.C. wakes up to the promise of vouchers after years of frustration with the idea of reform. What begs for recognition is that the Tweed Trust cannot be reformed; it can only be broken up to create space for a private market in education.