As the first half of the school year comes to a close next week, the stock-taking shows that the chancellor, Joel Klein, faces a famous battle against the teachers union to see through the project of putting — as he calls his program — Children First. The unionized teachers are promoting their own plan, which can be called Teachers First. The city can win if the mayor and chancellor:

Charge ahead on charters: Charter schools are not a sideshow but are at the core of putting children first. These publicly funded, privately run schools are exempt from most of the bureaucracy — notably the work rules of the teachers’ contract — that makes it so impossible for principals to run effective public schools in the city. But there are only 24 charter schools in operation in New York City, compared to about 1,100 public schools. So charter schools represent only about 2% of the schools. And since charter schools tend to be smaller than other public schools, they serve even fewer than 2% of the city’s pubic school pupils. Mr. Klein’s vision, if fulfilled, would give New York City about 80 charter schools, bringing their share of enrollment to about 7%.

Getting Mr. Klein’s 50 schools will require the Legislature at Albany to raise or remove the cap on the number of new charters that can be granted schools statewide. That cap stands at 100. Since the Legislature, cowed by the teachers unions, is unlikely to remove the cap, Mr. Klein might want to push a more limited proposal. One that stands out is a proposal that the state’s Board of Regents came close to promoting this month, which would exempt charter schools approved by the local school district from counting toward the statewide cap. Mr. Klein will have an opportunity to call for such an exemption when he testifies before the Legislature early next year.

Press for vouchers: If charter schools are progressive, vouchers are revolutionary. Charter schools remove a layer of bureaucracy, but vouchers give low-in come parents entrée into an entire universe of innovative, non-bureaucratic choices — including religious schools. As the Court of Appeals and various liberal interest groups try to shovel more money into New York City’s schools, where so much money has been wasted before, Catholic schools have been doing the job better and for far less money for each pupil educated.

With the Supreme Court’s approval of vouchers last summer, there’s no reason New York City couldn’t launch its own pilot program, as some smaller cities have. Demand exists. When private philanthropists offered 7,500 scholarships here to New York City private and parochial schools in 1999, applications were filed for nearly 170,000 students. That’s about 15% of the public school population. If the teachers unions bar spending public money as an experiment, perhaps Mr. Klein could expand the public-private model he has employed with regard to charter schools. To foster his 50 charter schools, Mr. Klein set up the New York City Center for Charter Excellence, a nonprofit, to help cover building costs. Why not create a New York City Center for Choice in Education to provide privately funded school vouchers to some of New York’s neediest children?

Hold out for the right contract, or none:

The United Federation of Teachers’ president, Randi Weingarten, has made one important point in her, and her union’s, defense. There have been two parties every time the teachers’ contract was renewed and revised, meaning that recent mayors bear as much responsibility for what is in there as does the union. Since Mr. Bloomberg has asked to be held accountable for the performance of our city’s schools, voters can assume that the city’s signature on any revised contract will mean that the mayor and the schools chancellor have fought for and won significant work-rule concessions that will allow them, and the city’s principals, a freer hand in running the city’s public schools.