THE DEPARTURE of William R. Hite Jr. as Prince George’s County school superintendent is a squandered opportunity. Not only is it a giant step backward for a school system that showed encouraging improvement under his leadership, but it’s also a serious blow to efforts to make the county a more desirable place to live and do business. Mr. Hite is the second superintendent to leave out of weariness with the county’s highly charged political environment; that should be a wake-up call to elected officials about the need for reform.

Mr. Hite announced Friday that he had accepted an offer to become schools superintendent in Philadelphia. Saying that he was happy with the progress made since 2008 when he took over leadership of Prince George’s 123,000-student system, Mr. Hite said that Philadelphia, with 146,090 students, represented an opportunity to make an “even greater impact in a larger system.”

There is no denying the challenges that await Mr. Hite in Philadelphia. Just how difficult his new job will be was captured in the question posed Monday by the Philadelphia Daily News about the city’s incoming superintendent. “Is he out of his mind?” the newspaper asked as it detailed problems — near-insolvency, resistant unions, hostile state lawmakers — that redefine the word “embattled.” Indeed, some officials in Prince George’s had hoped that the severity of Philadelphia’s troubles would, in the end, persuade Mr. Hite to reject its offer and continue work in Prince George’s that has produced a rise in student achievement.

That wishful thinking overlooks the climate of political interference and infighting in Prince George’s that fueled Mr. Hite’s frustration and drove the merry-go-round of superintendents — five since 1999 — that denies the schools the stability needed to bring about lasting change. “Montgomery County had Jerry Weast for [12 years], and we can’t keep a superintendent for five years over here,” former school board member Howard Stone told The Post’s Ovetta Wiggins. “It just doesn’t send a good signal . . . .”

Mr. Hite’s contract requires him to stay 120 days to ease the transition, but there is no indication it will be a smooth process. No natural successor to Mr. Hite exists, and his highly regarded deputy, who would have been the logical interim choice, has already resigned to take another job. The county Board of Education, itself a source of conflict, faces its own overhaul after elections in November that could see three members under the age of 21 taking office.

When the possibility of Mr. Hite’s resignation was disclosed last week, we urged County Executive Rushern L. Baker III (D), who has made education a priority with the appointment of a special commission, not to rule out the possibility of assuming control of the county’s education system. The loss of Mr. Hite is further argument for the county executive to take charge of an area that is crucial to the county’s overall well-being.