An arbitrator recently ruled that the Bloomberg administration could not go forward with plans to close—and then reopen—24 failing schools throughout the city. Why not? It would be wonderful to report that the arbitrator found that the city hadn’t gone far enough on behalf of students. But, alas, that’s not the case. Instead, the arbitrator contended that the plan violated labor contracts.

So it’s all about the teachers—and the teachers’ union.

Not surprisingly, the United Federation of Teachers and the Council of School Supervisors and Administrators initiated the opposition. By closing and then reopening the schools, the city could have replaced principals, vetted staff and hired back fewer teachers. Those with a stake in the status quo found this unacceptable. They always do.

The city’s plan is tied to efforts to win $60 million in federal education funds. The arbitrator’s ruling puts that funding in jeopardy and has only added to confusion and chaos in the 24 schools.

One thing, however, is evident: The forces of the status quo continue to show that they have little interest in transforming public education in New York. They have resisted evaluation, accountability, tenure reform and other changes. Their allies in the state Legislature and elsewhere have aided and abetted in this active resistance to reform.

Mayor Bloomberg and Schools Chancellor Dennis Walcott promised to appeal the arbitrator’s decision. “We will not give up on the students at these 24 schools,” they said.

At least somebody is thinking about who really benefits from school reform.

Mayor Bloomberg and others believed in full and unfettered access to teacher performance evaluations. They made the case that transparency would only help the effort to encourage good teachers and weed out the bad ones.

Unfortunately, the governor and legislators decided to limit access to the data to parents, who will be able to review evaluations of their childrens’ current teachers. While that’s better than nothing—and bear in mind that the unions fought the whole idea of performance evaluations to the bitter end—it’s a far cry from the sort of transparency that Mr. Bloomberg and his allies sought.

Performance evaluations are conducted by public officials using public resources. The public, then, has a right to see the data. That seems simple enough. In fact, it’s already happened. Several months ago performance evaluations for some 18,000 city schoolteachers were released to the public and published in several newspapers. The world did not come to an end. Angry parents did not march on their local public schools (although perhaps they should have). Some teachers were embarrassed, but as public employees, their flaws—and their strengths—ought to be accessible to taxpayers, who are, after all, their ultimate bosses.

The teachers’ unions used every ounce of their considerable political power to prevent wide dissemination of the evaluations. Their success should remind us all that the unions remain a formidable obstacle in achieving genuine school reform. Some might have concluded that recent reversals, including the implementation of performance evaluations, had hobbled the unions. Not a chance.

Mr. Cuomo’s actions here are disappointing. He quite literally introduced the compromise measure under the cover of darkness—the bill was made public just before midnight on June 18. If he was embarrassed, well, he should have been.

Legislators were no better. The state Senate passed the bill after a “debate” that took up all of six minutes. Only one senator voted against. The Assembly’s debate was quite a bit longer, but that’s only because the union’s minions in the Assembly were not happy with the very concept of evaluations in the first place. Eventually, the Assembly passed the bill with little opposition.

Reformers at every level of government rightly demand greater transparency from public officials and, in fact, from private corporations as well. We all live with the effects of secret deals made in the private and public sectors. Transparency is critical in politics as well as in finance.

Limiting access to teacher performance data is a defeat for transparency. And for valor.