How is this possible? Most of us want integrated public schools, but it’s not going to happen. Why not? As Nikole Hannah-Jones insisted in a recent interview, school segregation isn’t the result only of racist or white-supremacist feelings, but rather of a basic, ugly truth about what schools are really for.

It’s not something we like to talk about. We like to think of our public schools in Horace Mann’s terms. In his famous 1848 report, Mann called schools the “great equalizer.” For Massachusetts and America—Mann argued just as the spectre of communism stalked Europe—common schooling would temper the growing class divide. Instead of a revolution, Mann dreamed, common schools would help America gently rise up, all together. Ever since Mann’s day, politicians insist and assume that public schools can save America. Everyone from Barack Obama to Betsy DeVos harps on the notion that schools can make America more equal, more fair.

There is truth in that dream. We can all recite cases of extraordinary students and families who have used unequal schools to overcome difficult economic circumstances. Public schools really can offer opportunities to talented, hard-working people.

70% of us want more integrated schools, but 99.9% of us want something else more.

As Hannah-Jones points out, though, there is another, more powerful purpose for schooling in these United States. Like it or not, this second vision will always trump Mann’s vision of school as the great equalizer. It’s not that white parents don’t want their children to go to integrated schools. They do. As recent poll results suggest, large majorities of parents want integrated schools.

The problem is something different. Hannah-Jones agrees that many white parents in her Brooklyn neighborhood, for example, love the idea of “curated diversity.” They want a smattering of non-white children to share their children’s high-quality schools. And they love the notion that their children will go to school with the children of affluent African Americans.

But they recoil from the prospect of having their children go to schools dominated by low-income non-white children. Why?

Because, as Hannah-Jones puts it,

Even in a community where the schools pretty much suck, if there’s a school with black kids, it’s going to suck worse.

In other words, many white progressives want their children to go to diverse schools. What they won’t abide, however, is that their children will be subjected to the terrible public schools that are the common fate of low-income families.

It comes down to an often unstated but fundamental purpose of American public education: For many parents, For most parents, the primary purpose of education is not actually to make children smarter or better in general. Those might be worthy goals, most people assume, but in fact the primary purpose of education—the way most Americans see it—is to give their children an advantage in the fight for good jobs and sweet lives. As Hannah-Jones says,

if one were to believe—which I believe—that having people who are different from you makes you smarter, that you engage in a higher level of thinking—and there’s been research that shows that—that you solve problems better, there are all these higher-level ways that integration is good for white folks. . . . those are all hard soft-arguments to make to people who fundamentally view education as, how my kid will rise to the top above every other kid and get into Harvard. They don’t actually give a damn about their kid being a better person.

It may sound excessively gloomy, but Hannah-Jones is depressingly right. When we stack up the politically active parents who want to use their children to help make society more equal against the parents who want to help their children squeeze every affordable advantage out of schooling, the equalizers will always lose.