Which D.C. mayoral aspirants would keep D.C. Schools Chancellor Kaya Henderson? The answer to that question drove many people’s votes in the April 1 Democratic primary. But concern about stability in D.C. Public Schools appears to begin and end with the chancellor.

What about principals?

Henderson can offer data points and engage in 21st-century edu-speak ad nauseam. But dramatic improvements cannot be achieved — or sustained — without the continuing direction of strong leaders in the schools.

Former superintendent “Paul Vance used to tell us we are the field generals. We were the ones that had to put the battle plans into effect,” said one principal, who, like the others I spoke with, requested anonymity, citing fear of reprisal. “I don’t get the sense that people downtown see us that way anymore. . . . They are pretty condescending.”

Last summer, at least two dozen principals were replaced. That trend continues this year. Mary Levy, an education consultant who has spent two decades studying DCPS, said the turnover rate among the District’s 108 principals is higher than in surrounding school systems. “Every year about 25 percent of schools change their principals. That means principals don’t have a chance to build any kind of programs,” she said. By comparison, turnover last year in Montgomery County was “between 5 and 7 percent.”

“It’s this constant churn,” said Aona Jefferson, head of the Council of School Officers, which represents principals, assistant principals and other non-teaching staff; the group reached a tentative labor agreement with DCPS this month, but it did not include a controversial principal evaluation system. Jefferson said she has urged Henderson to move from annual contracts to multi-year contracts for school leaders. “The revolving door needs to stop. ”

DCPS spokeswoman Melissa Salmanowitz said a “task force is exploring the idea of multi-year contracts and preparing a set of recommendations for the chancellor.” She also confirmed that there are principals “moving on,” adding that “there are many reasons why school leaders choose to leave.”

Among schools losing their principals are Oyster-Adams Bilingual School, H.D. Cooke Elementary School, Lafayette Elementary, Hyde-Addison Elementary, Savoy Elementary, Hearst Elementary and Duke Ellington School of the Arts, according to DCPS and government sources. I am aware of three other schools that may be getting new principals.

Salmanowitz would neither confirm nor deny that principals are leaving specific schools, noting DCPS’s policy to present a complete list of “schools where there will be a leadership transition; we anticipate releasing that list in the coming weeks.”

A few principals are being pushed out. Others are fed up, particularly with the central office administration, and have decided to leave. Several complained to me of being unable to meet with the chancellor for any substantive communication during the past year, even for evaluations. They also said there had been a lack of collaboration. Further, they cited micromanaging by Henderson’s team, including a demand that a bureaucratic waiver process be followed before instituting needed programs.

“There is an overall sense a principal’s job is not respected,” said another principal.

Some departing leaders were just beginning to turn their schools around; others have solid records of achievement. Lafayette’s principal, for example, received the 2012 Rubenstein Award for Highly Effective School-Leader at the fancy “Standing Ovation” shindig held each year at the John F. Kennedy Center for the Performing Arts. The White House has heralded Savoy Elementary under Patrick Pope’s leadership. He has ushered in remarkable changes in the lives of students and their families.

What’s going on with DCPS? Are Henderson and her data-driven crew too enamored of their own headlines? This much is clear: Sending droves of principals out the door each year won’t help D.C. children. Instead of alienating good principals, the chancellor should clone them.

Some folks blamed Jason Kamras for principal dissatisfaction: “He has redefined what it means to be a principal,” said a third principal.

Kamras is the head of human capital — plainly speaking, human resources director. He catapulted to the administrative class after winning the 2005 National Teacher of the Year award; he taught math at John Philip Sousa Middle School. He was never a principal, yet he is responsible for evaluating them.

“Teachers and principals are certified in their jobs,” noted Jefferson. “That [standard] should be reflected throughout the system.”

Kamras’s model for evaluating principals was publicly criticized this year. The Post’s Emma Brown reported that principals said they hadn’t been fully informed and expressed “shock” when they received their ratings last fall. They had been grouped into four categories: ineffective, developing, effective and highly effective. Nearly half were considered “developing,” and 8 percent were “ineffective.” Kamras initially rejected the criticism, but he made adjustments.

One of the principals with whom I talked was rated “minimally effective,” and another was considered “developing.” Both had high rates of students who are proficient or advanced in reading and math. Salmanowitz, the DCPS spokeswoman, said that no one “has complained to us about poor evaluations.”

Is that because they can’t get an audience?

Salmanowitz said DCPS appreciates the “stability of our long-term principals” and their hard work. “However, we are also thrilled by the caliber of school leaders who are attracted to a rapidly improving school system, many of whom would never have previously considered DCPS.”

Translation: Let the principals leave; there are others to take their place. Ouch.

Is that anyway to run a school district?