Is the ghost of George Wallace running New York City’s public schools? Jonathan Kozol’s new book, “The Shame of the Nation,” makes it seem so. Visiting New York schools, Mr. Kozol “cannot discern the slightest hint that any vestige of the legal victory embodied in Brown v. Board of Education … has survived …” Somehow, the heartland of American liberalism has become the living embodiment of Governor Wallace’s ideal: “Segregation today, segregation tomorrow, segregation forever.”

Mr. Kozol luridly refers to “the restoration of apartheid schooling,” betraying a stunning ignorance of the nation’s racial history. When Governor Wallace stood in the schoolhouse door in 1963 to bar the court-ordered entry of black students, he was indeed defending a system of apartheid. Not a single black child in Alabama attended a public school with any white pupils. Public schools – and all other public facilities – were strictly color-coded by law.

By now, of course de jure segregation has vanished from the land. But the term segregation lives on, packing a powerful moral punch with its evocation of black subordination and separation in a Jim Crow America.

But what does it mean to say that New York City’s schools today are highly segregated? The definition used by academics like Gary Orfield of the Harvard Graduate School of Education, and popularizers like Mr. Kozol, is quite astonishing. Schools, they say, are segregated if non-Hispanic whites are a minority of the student body. The reports of Mr. Orfield’s Harvard Civil Rights Project bristle with tables indicating how many black, Hispanic, and Asian students attend schools with white enrollments of less than 50%. Such schools are presumed deficient by definition.

With segregation redefined by semantic sleight of hand, it is no surprise that New York City has a great many segregated schools. Only one in seven of the million-plus students enrolled in the city’s public schools is white. Blacks are over a third of the total, and Hispanics nearly 40%, with Asians making up another seventh. Minority kids are thus 85% of the city’s public-school population, Inevitably, majority-white schools are rare.

Enrolling minority students in majority white schools would require a massive city-to-suburbia busing program, and many students would need to travel a great many miles to avoid “segregating” the schools in the closest suburbs, which tend to have a substantial minority presence already. Here is the mind-boggling fact: to bring white enrollments up to 50% in the New York City schools, it would be necessary to bus nearly 400,000 students out of the city each day, and fill their seats with about 400,000 whites from suburbia.

Furthermore, the experience of large-scale mandatory busing programs in cities like Boston and Denver suggests that its most important long-term result would be to drive families who could either move beyond the reach of busing or afford private or parochial tuition out of the system. Finding majority political support for such a scheme is so wildly unlikely that is hard to believe that anyone truly takes the idea seriously.

A serious plan to increase the number of majority-white schools would require that we explore other possibilities. The most dramatic demographic change affecting the city’s schools in the past three decades has been the explosive growth of the Latino student body. Lowering the national immigration quota and cracking down on illegal immigration would reduce the number of Hispanic youngsters in the schools. Since the shortage of white pupils is the heart of the problem, we could experiment with policies designed to bring white families with school-age children back into the city. A $1,000 a month rent subsidy for whites who would promise to send their kids to P.S. 98, for example, would likely find a significant number of takers. Or how about evicting current occupants of rent-controlled apartments and replacing them with newcomers who agreed to these conditions?

Such schemes are admittedly far-fetched, though no more far-fetched than a massive new busing scheme. They might merit discussion, though, if it were indeed true that minority children simply cannot learn enough unless they experience the leavening presence of a white majority among their classmates. This idea, the premise for all the angst about “segregation,” is both preposterous and morally offensive.

Fortunately, the evidence does not show that children need any particular racial mix in their school in order to do well. The Supreme Court concluded correctly in Brown v. Board that the legally-enforced separation of the races delivered a message that black children were inferior, with their learning impeded as a result. But the abundant social science literature produced since 1954 shows that, in the context of minority concentrations reflecting demographic reality, the racial composition of a school affects student performance very little if at all.

Mr. Kozol, in looking at the South Bronx, sees a picture no different than that in the South in 1954. “We have, it seems, been traveling a long way to a place of ultimate surrender that does not look very different from the place where some of us began,” he writes. Maybe he and his supporters across the political spectrum should try looking at the academic results of the all-minority KIPP Academy Charter School in the South Bronx – just for starters. Were the segregated schools in Mississippi a half century ago really no different?

The Thernstroms are authors of “No Excuses: Closing the Racial Gap in Learning.” Mr. Thernstrom is Winthrop professor of history at Harvard and Ms. Thernstrom is a senior fellow at the Manhattan Institute.