Plans by Mayor Bloomberg and his schools chancellor, Joel Klein, to open 50 new charter schools in New York over the next five years may be thwarted by the 100-school cap in the state law that authorized charter schools. The New York Charter School Association and several far-sighted lawmakers in Albany are backing an effort to lift the cap. That would allow Mr. Bloomberg and Mr. Klein and their fellow backers of educational innovation to move forward in creating more such schools, which are government-funded but are exempt from many of the regulations that apply to conventional government-run schools. Mr. Klein offered a terrific explanation of his support for charter schools in a too-little-noticed March 27 speech, which we reprint on the opposite page.

Mr. Klein’s speech makes many of the common arguments for charter schools. It speaks of excellence in the context of “meritocracy” and of being “entrepreneurial.” It says that “more rules and regulations” aren’t the path to success. We wish he’d follow this line of reasoning to its logical conclusion and embrace vouchers, but it’s still a remarkable speech. What we particularly appreciate is the straightforwardness with which Mr. Klein anticipates and demolishes the objections to be raised by his enemies in Albany. The New York Sun’s William Hammond, for instance, in the weekend paper quoted the chairman of the Assembly Education Committee, Steven Sanders of Manhattan, as saying the existing 100-school cap should remain in place until the existing charter schools have developed a “track record.”

It is here that Mr. Klein’s speech is eloquent, with respect to the track record of the alternative to charter schools: the government-run public schools.

Here’s what New York’s schools chancellor had to say: “Public education in large urban areas in the United States has failed.…New York City is actually one of the best urban school systems in the country, but by any measure, I guarantee you that at least half, probably more than half, of our students are not remotely getting the education they deserve.”

Based on that track record, the state legislature and Governor Pataki would do well to move swiftly to lift the cap and create more alternatives for parents stuck in a system that, as Mr. Klein put it, “has failed.”