Union Victory in L.A. Schools Showdown Ups Ante

After edging out charter operators, United Teachers Los Angeles now must deliver.

In Los Angeles, where teacher groups and charter schools engaged in a head-to-head competition to operate schools in the sprawling urban district, teachers have emerged—to the surprise of many observers—as the clear winners in the latest showdown.

With the management of 12 existing schools, all of them low-performing, and 18 new campuses up for grabs under the city’s “public school choice” policy approved last summer, the Los Angeles Unified Board of Education late last month voted in favor of teacher-led proposals in all but six cases. More than 40,000 students will attend the newly managed schools this fall.

Charters, which many had expected to be the dominant players, were largely left out, including three of the city’s most successful operators, whose proposals to run new schools were endorsed by Superintendent Ramon C. Cortines. But in his full slate of recommendations to board members on which groups should manage the schools, Mr. Cortines also favored some internal...