In this file photo from 2011, Michael Woods teaches prekindergarten children during a class at LEAP Academy at KIPP DC. KIPP is a high-performing public charter school network. (Astrid Riecken/For The Washington Post)

I have been exchanging emails with Diane Ravitch, the clearest voice in the movement to reverse American emphasis on raising school achievement no matter what. She is a brilliant historian and essayist, even if she does not share my fondness for this century’s biggest education reform: charter schools.

We agree that disadvantaged children have to be rescued from poverty before most of them can learn as much as middle-class kids. But while the country struggles to make that happen, why can’t we, in the meantime, support those public charter schools that are preparing significant numbers of low-income children for college?

Charter schools are still growing. There are about 7,000 in 42 states and the District. They have 3 million students, six times more than 15 years ago. I have visited more than 50 great charters, but I know that many others are bad.

In 2015, 400 charters opened while 270 were closed for lack of students, money or academic success. The NAACP wants a moratorium on charter expansion. Voters in Georgia and Massachusetts just turned down measures to increase charters. Education Week found that low-performing cybercharters are still getting state money because of heavy lobbying by their corporate sponsors.

I asked Ravitch: Would you shut down charters altogether, even if some were run by dedicated educators who were giving students more than they got in their regular public schools? At this critical moment for charter schools, with Ravitch so influential on the anti-charter side, her answer is important.

“I would call a moratorium for all new charters,” Ravitch said. “All charters would be required to be financially and academically transparent.” She would ban for-profit charters. Charters would have to fill all empty seats each year, she said, so average test scores would not rise just because low-performing students had left. Charters would have to have the same demographics as regular schools in their neighborhoods, she said, with the same portion of students with disabilities and students learning English.

Ravitch also would require characteristics that the best charters already have: collaboration with public schools, charter boards made of local community members and racially diverse student bodies.

Ravitch’s ideas are worth discussing, but she has not eased my fears about what would happen to the best charters. Their successes depend on giving their principals and teachers the freedom to innovate.

I asked her: “Would charters be allowed to continue fundraising for themselves? Would they be able to keep their longer school days, year-end field trips, training programs for inexperienced teachers . . . and more intensive classes for special education kids, which require more money? Would they still have the freedom to use their own curriculums?”

Ravitch responded with one word: “Yes.”

She reminded me that “the charters in some states are dreadful.” Washington-area residents familiar with the high standards and sensible management of D.C. charters would be appalled at what is going on in Michigan, Ohio and Nevada.

My only strong disagreement is with her desire to “oppose charter schools unless they are part of a district plan, unless they meet a need that the school district wants to fill.” This presumes that the people who run school districts have a clear sense of what their students need. If that were true, the charter movement would never have started.

Toward the end of our exchange, the election results came in. “There will be neither accountability nor transparency for charters in a Trump administration,” Ravitch told me. “If charters don’t clean up their house, they will be known for graft, fraud and waste of taxpayer money.” Does Trump care at all about this? We shall see.

Ravitch is among the nation’s toughest charter critics. But she is willing to let charter educators be creative. This is encouraging as we seek middle ground for a reform that, despite its problems, has had many successes and strong support from parents.