These are worthy goals—and not one of them is necessarily incompatible with many reformers’ own aims. Yet Ravitch doesn’t address competing priorities or painful trade-offs. Further reducing class size in better-off suburban districts, for example, may leave less money for more urgently needed early-childhood programs in poorer communities.

Ravitch the counterrevolutionary may be right that the reformers’ cause is primed for derailment. But Ravitch the historian once foretold what typically follows a contentious drive for school improvement: “It was usually replaced,” she observed in 2003, “by a movement called ‘back to basics,’ or ‘essentialism,’ ” which didn’t herald new progress but rather “a backlash against failed fads.” Ravitch herself is the “essentialist” now, urging that we go back not to basics but to a past when issues of equity and adequate funding dominated debates about education. At a time of growing income inequality, this correction is overdue.

But let’s not get too nostalgic about those old debates. There’s a reason the younger Ravitch was impatient decades ago to discover new choices for families in America’s worst-off districts. I hope I’m not alone in searching her new book for traces of the writer who, as recently as 2010, could still see beyond a politicized landscape to understand what draws many hard-pressed parents to charters. They’re not set on this curriculum or that pedagogy, as some reformers suggest. They’re looking, as Ravitch appreciated, for academic “havens”—which is what parents at the inner-city school where I teach, once nominally parochial and now a charter, often tell me. They want a place where their children can join peers already driven to achieve in school—a search with another bleak trade-off. The departure of these students leaves other peers, without parents resourceful enough to find better alternatives, stranded in schools that become all the harder to improve.

In Reign of Error, Ravitch does outline the beginnings of a potential compromise with her former pro-charter allies, which she isn’t trumpeting on Twitter, but should be. Instead of trying to eliminate charters altogether, she sounds ready to work toward making them better. Some of the greatest failures and outright frauds of the charter movement, she rightly observes, are in its for-profit sector. Schools shouldn’t be in the business of figuring out how to maximize investor returns—in fact, they shouldn’t be in business at all. No top private or parochial school operates this way. Ravitch is less persuasive when she attacks charter networks. Why not scale up programs that work? Some of the best charters, like KIPP, are chains run by nonprofits.

If the reform movement hopes to retain the public’s trust, insisting that reputable charters expel their for-profit brethren is a sensible place to start. Ravitch also argues convincingly that charters should accept a fairer share of the toughest-to-educate students. For her part, Ravitch might lead her own followers to recognize that the desire to improve teacher quality isn’t tantamount to teacher-bashing.

“If my child were in a school where he was not learning,” Ravitch wrote in the not-too-distant past, “I would not wait for a gathering of social scientists to tell me whether it was okay for me to put him in another school.” A reform movement convulsed by extremism shouldn’t hinder parents, or children, either. If only Ravitch, too, would dedicate her zeal to a less divisive vision.

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