D.C. Public Schools Chancellor Antwan Wilson at Ludlow-Taylor Elementary School on Feb. 2. (Astrid Riecken/For The Washington Post)

IT DID not take D.C. Mayor Muriel E. Bowser (D) long to realize there was no way Public Schools Chancellor Antwan Wilson could survive his violation of school policy that allowed his daughter to get preferential treatment for enrollment in one of the city’s most desirable high schools. On Tuesday — just days after saying she wanted Mr. Wilson to continue in office — she asked for and received his resignation. Mr. Wilson’s actions called his judgment into question, and it was clear he would not be able to regain public confidence. It was the correct call.

Nonetheless, the upheaval represents a setback for the public school system at a precarious time. Mr. Wilson had been in office for only a year, and so the continuity that is important to school improvement is lost. What makes the churn and uncertainty even worse is that Mr. Wilson’s dismissal under a cloud comes as the system is dealing with another controversy, this one rooted in the previous administration, over graduation rates.

The back-to-back scandals have caused some to question the school reforms ushered in under mayoral control. Such thinking is shortsighted. The school system that exists today is a far cry from the sorry state of affairs a decade ago when schools didn’t open on time, teachers went unpaid, expectations for students were low and parents fled the system. The seriousness of the problems related to inflated graduation rates can’t be discounted, but that does not negate what has been accomplished under school reform. In addition to building a prekindergarten system, rigor has been added to the curriculum, new instructional strategies have been introduced and the teaching force has been transformed into a performance-based profession. Enrollment is up, and test scores, including on the highly regarded “nation’s report card,” show improvements in student achievement.

Major problems remain. Too many students are not proficient in reading and math, an achievement gap between white and minority students persists, and there are — as evidenced by Mr. Wilson’s special pleading for his daughter — still too many schools that don’t deliver. But abandoning high standards and accountability is not the answer.

The selection of a top-notch replacement for Mr. Wilson will be critical. The recent scandals and this year’s city elections may make that harder. But the schools cannot afford another false start.

Amanda Alexander, chief of DCPS’s Office of Elementary Schools, who started in D.C. public schools as a kindergarten teacher in 1998, will run the schools on an interim basis. She has her work cut out for her, and we wish her success.