Gov. Jay Nixon is a key figure in the stability of St. Louis Public Schools. There’s no avoiding it — the district’s hard-fought battle to restore its credibility depends on Mr. Nixon’s early support for its leadership.

When the state Board of Education invoked the state’s takeover law and stripped the district of its accreditation in 2007, Gov. Matt Blunt appointed Rick Sullivan, former chairman of McBride & Son, a national homebuilder, to head the Special Administrative Board that oversees the district. Mr. Sullivan took over on June 15, 2007.

The other two members are Melanie Adams, a program director at the Missouri History Museum appointed by Mayor Francis Slay, and Richard Gaines, an insurance executive appointed by St. Louis Aldermanic President Lewis Reed.

Mr. Sullivan’s three-year term comes to a close in less than a year. It may seem as though there’s no urgency for Mr. Nixon to reappoint him or make his intentions known. But if a lame-duck chairman heads the SAB, the district’s momentum could be halted. The steps the district has taken toward regaining its accreditation could be reversed.

Mr. Sullivan has earned the opportunity to continue the steady progress in the district. Mr. Nixon should not let the issue linger unless he’s prepared to take full political responsibility for the district’s success or failure.

The SAB inherited a district riddled with vacancies in top positions, hemorrhaging students and facing deficits as far as the eye could see. Mr. Sullivan and his colleagues have had to make deep budget cuts, $53 million in the coming school year alone.

They have led an open and inclusive debate on the future of the district’s school buildings — culminating with the closing of 17 buildings. They reached a new collective bargaining agreement with teachers; successfully defended a lawsuit challenging their authority; developed a comprehensive school improvement plan (as they are required to do under state law) and hired a well-regarded new superintendent, Kelvin Adams, who has a made a big impression since starting work in November.

Above all, Mr. Sullivan and his colleagues have brought order and seriousness of purpose to the district’s public proceedings, a desperately needed change from the conflict and chaos that preceded the district’s loss of accreditation.

The SAB members don’t agree on all matters. But they’ve engaged in a constructive give and take. They have freed Mr. Adams from distractions, enabling the superintendent to focus on the central mission of raising student achievement.

As Mr. Nixon weighs his options, he should reflect on the conditions that contributed to the Board of Education’s decision to pull the district’s accreditation: “poor academic performance, frequent changes in executive leadership, declining enrollment, deteriorating finances, loss of public confidence and persistent conflicts within the board of education and between the board and a series of superintendents.”

To leave Mr. Sullivan in limbo or, worse, to replace him would invite more disruption, as yet another leader would try to surmount the steep learning curve of this complicated institution.

Former Secretary of State Colin Powell famously invoked the “Pottery Barn Rule” when he argued against military intervention in Iraq with President George W. Bush: “You break it, you own it.”

So it goes with Gov. Jay Nixon and St. Louis Public Schools.