Alex Maclean/ Getty

One can see why Joe Biden wasn’t too worried about the busing issue. Sure, he had teamed up with segregationists in 1975 to cut the legs out from under federally mandated integration busing. Sure, he’d even called busing a “domestic Vietnam.” But for decades, that choice was shielded by a durable political consensus: Busing was and always would be a political disaster, beyond any hope of resurrection, and toxic to even talk about.

So when Kamala Harris used the first Democratic presidential debate to skewer the former vice president over his civil-rights record, Biden seemed floored. He found himself face-to-face with something politicos had thought extinct: a busing defender. More than that, a busing beneficiary. It was as if the arc of history, after decades of slowly bending toward justice, had opted to land directly on Joe Biden’s head.

Few could deny that the showdown made for exceptional political theater, but almost as soon as it was over, some pundits rushed to their keyboards to remind everyone that reviving historic debates about school desegregation was no way to win an election. Analysts wondered whether the issue would be a drag on Democrats in 2020. Conservatives crowed in disbelief. Liberals applauded Harris’s performance—and suggested she change the subject. Even Harris herself wavered, later saying that current circumstances may not require busing to be imposed by the federal government.

Nonetheless, in the weeks since, school desegregation has unexpectedly found itself in the public eye once again. Scholars have used the moment to chip away at resilient myths about busing, explaining how it was only one component of federal desegregation plans, one that was intentionally targeted and demonized by white segregationists. Others have pointed out that, as a method of producing school integration, court-ordered busing was generally effective.

One idea has gone largely unchallenged, though: that fighting for school desegregation is potentially a career-ending cause for a politician, rendering strong civil-rights leadership pointless, if not outright foolish. But that idea deserves to be challenged, too. When it comes to desegregation, the political class has learned its historical lessons from an America that no longer exists.  

At first glance, it doesn’t seem possible to overstate the political dangers of school integration. Battles against federal civil-rights initiatives loomed over three decades of recent American history following Brown v. Board of Education in 1954, and ended with integration skeptics in power and segregation still in place. The later stages of the civil-rights movement, including many attempts at school integration, died in the choking collar of white suburbs that surrounded America’s big cities. Efforts to integrate housing in those suburbs were abandoned after backlash in the 1970s—and were essentially forgotten until the Obama administration. Suburban resistance to school integration continued for years after that, but was no less tumultuous.

Fear of integration in white suburbia distorted political outcomes in shocking ways, such as when the segregationist George Wallace, after stumping around Detroit’s white working-class suburbs in opposition to busing, won the 1972 Michigan Democratic primary in a surprise rout. Richard Nixon campaigned vigorously against busing, which helped propel his landslide victory over George McGovern. Fear of integration distorted America’s metropolitan landscape, too. When large cities were ordered by federal courts to desegregate their schools, many white parents simply fled across the city border into a suburb, creating deeper segregation in urban neighborhoods. In the infamous 1974 Milliken v. Bradley decision, the Supreme Court held that federal courts could not typically include suburban districts in a desegregation order, ensuring that those districts would remain easy vectors for white flight. (It’s no coincidence that the regions with the most sustainable school-desegregation programs were those, like Louisville and Raleigh, where cities and suburbs were included in a single unified school district.) When metros were divided into many school districts, such as Detroit or Boston, inner-city schools frequently collapsed into poverty and segregation, while schools in nearby suburbs remained white and affluent.

Census data from 1980, shortly after court-ordered desegregation crested, show the city-suburban racial divide. In major metros, a large majority of white residents—more than three-fourths—lived in a suburban community. The average suburban neighborhood was 85 percent white. Meanwhile, more than half of nonwhite residents, and three-fifths of black residents, lived in a central city. In short, even after the civil-rights movement and court-ordered busing, the borders of major cities still served as racial borders. Venture outside the city line, and in most parts of the country, one would almost inevitably enter a vast patchwork of overwhelmingly white communities.

Historians of desegregation like Matthew Lassiter and Kevin Kruse have suggested that the fundamental conflict between exclusionary white suburbs and diverse cities helped define the whole course of American politics after the 1960s. Even half a century later, politicians and pundits see suburban borders as a firewall against racial integration. Many believe that any plan or policy that crosses the firewall risks once again mobilizing the silent majority lurking in the white hinterland. The perceived risk climbs higher when compulsory measures are invoked. Many school-diversity proposals circa 2019 are geographically siloed: Cities are welcome to improve their schools, and suburbs should not ignore questions of racial equality, but only a political naïf would try to integrate one into the other. And heaven help those who would bus a child across the boundary line.

But there’s a problem: While the trauma of the 1970s and ’80s seems to have locked these ideas in the national memory, the country itself has not stopped changing. The America of today is diversifying at a rate that’s often overlooked. And as that happens, suburbia’s uniform whiteness is disappearing. The suburban firewall isn’t just endangered—in a huge number of places, it has already fallen.

Look at the 50 largest American metros. By my analysis of U.S. Census Bureau data, in 1980, more than half the population of those regions lived in neighborhoods greater than 90 percent white. Today? That lopsided pattern is only preserved in a single large metro: Pittsburgh, America’s whitest major city. Overall, less than one-tenth of the national metropolitan population lives in a neighborhood that’s greater than 90 percent white.

Or consider that in 1980, white Americans in a major metro were more than 10 times as likely to live in a virtually all-white neighborhood than a “majority-minority” neighborhood. Today white residents are more likely to live in a majority-minority area—two and a half times more likely, in fact.

The scale of these national changes is too great to leave suburbs unaffected. As a consequence, white suburbanites are exposed to more racial diversity than ever before, a process that compounds annually. In 1980, a majority of white suburban residents lived in areas greater than 95 percent white, according to my analysis of the Census data. Only about one in six lived in a neighborhood where people of color made up at least 20 percent of the population. Fast-forward to today, and the numbers flip: Fewer than one in 10 white suburban residents lives in a neighborhood greater than 95 percent white, while more than half can be found somewhere that’s more than 20 percent nonwhite. Suburbs are now home to most black Americans and Hispanic Americans.

Nonwhite residents skew younger, which means diversity is increasing in schools even faster than in cities and neighborhoods. As that happens, the racial isolation of white children has been broken in spectacular fashion. In 1988, the earliest year with digitized federal data, more than half of white children nationwide attended a school that was more than 90 percent white. In 2016–2017, the most recent school year with data, that share dropped to less than one-fifth. In public districts today, more than three-fifths of white children attend a diverse school where at least 20 percent of the student population was not white; in major metros, nine-tenths of white children do.

Lest the point get lost in a swarm of statistics, these figures represent an inversion of America’s historic racial geography. As recently as a few decades ago, almost all white people in America lived their lives in places where racial diversity was minimal or nonexistent. This is simply no longer true. In neighborhoods and, especially, schools, moderate diversity is now the norm for most white Americans. The America where busing failed was a place where islands of urban diversity drifted in an ocean of suburban whiteness. Today, the metaphor must be reversed: An archipelago of white enclaves is embedded in a sea of growing racial diversity.

These changes have been driven by a handful of factors. The first is the rapid demographic shift of the American population. Immigration—mostly, but not exclusively, from Asia and Latin America—has eroded the size of the white majority. The legacy of the civil-rights movement has played a role, too. Laws like the Fair Housing Act made it harder to bar nonwhite Americans from suburban and affluent communities. Over time, more and more residents of color have moved into these places, many seeking the same safe neighborhoods and good schools that all parents want.  

None of this implies that segregation has been defeated. Intense nodes of residential and school segregation remain, particularly in the wealthiest and poorest communities. White flight still exists too, as the white population of diversifying suburbs abandons those communities for white, sprawling exurbs at the urban periphery. And counterintuitively, as all-white neighborhoods have grown rarer, people of color have, by some metrics, become more isolated. That’s because America’s rapidly increasing population of color has caused non-white-segregated neighborhoods to grow, even as white-segregated neighborhoods have shrunk. Caught in between is a wide array of cities and towns, temporarily integrated by the process of racial transition, but sliding toward renewed segregation.

Moreover, these changes have not been experienced evenly by all groups. Black Americans in particular remain more residentially segregated than most other racial or ethnic groups. More than two-thirds of black and Hispanic children are still educated in segregated schools, and that proportion has increased sharply over the past decade.

But if America’s changing demographics do not reduce the urgency of desegregation, they surely alter its politics. For starters, commentators frequently look at the conflagrations of earlier years and assume many white parents will react explosively to any influx of racial diversity into their schools or neighborhoods. Stable integration plans that persisted throughout the 1970s and ’80s were overwhelmed in the public mind by vivid instances of community violence: Klan bombings and neighborhood riots. But there is reason to believe that the increased diversity of America’s neighborhoods and schools will substantially mute such backlash today, making long-term success much more likely. Even if integration plans can still produce an angry community meeting, that’s a far cry from a mob of white parents attacking and overturning school buses carrying black children.

What’s different? For one thing, demographic shifts are much harder to perceive when a place is somewhat diverse to begin with. White parents are more likely to notice when the number of nonwhite children in a school increases from zero to 10 than when the number increases from 25 to 50. Additionally, it’s well known among social scientists that exposure to integrated environments—or “intergroup contact,” in the language of the academy—facilitates greater comfort with people of different races. Children who grow up in integrated schools are less likely to form racial stereotypes, more likely to form cross-race friendships, and feel more at home living and working in mixed-race environments. Or, put more straightforwardly, America’s present school and neighborhood diversity is helping create new white racial progressives. (This is also something to keep in mind the next time someone rails about the so-called PC obsession of the younger generation. There’s a sociological explanation: Most of that generation is being educated in schools far more diverse than those of their parents.)

Of course, one only needs to look at the 2016 election to know that reactionary racial views still command significant support in America. But scrutinize it a little closer, and even Trump’s election provides evidence of racial diversity gradually altering suburban politics. In the aggregate, even among white voters, Trump outperformed previous Republicans only in a narrow sliver of communities: suburbs and exurbs where more than 85 percent of the population was white. In places that were even marginally diverse, including the wealthy suburbs that had historically fought busing tooth and nail, Trump badly underperformed his Republican predecessors.

Perhaps even more important than shifting attitudes, however, is the way America’s changing demographics have altered who holds political power, gerrymandering notwithstanding. Before, it was clear where the majority of voters lived: uniformly white neighborhoods, served by uniformly white schools. These places were the traditional bulwark against integration efforts, breeding grounds for the civil-rights backlash that legislators and presidents learned to fear. They’ve been reduced to a minority. In some states and cities, a very small minority.

Consider New Jersey. Civil-rights groups recently filed a school-desegregation lawsuit against the state. The plaintiffs are seeking a statewide integration plan, which would help stabilize diverse schools and equalize opportunities in rich and poor cities. Not long ago, such a lawsuit might have been understood as a politically quixotic attack on white suburbia; as recently as 1990, 61 percent of New Jersey census tracts were predominantly white. But today, barely a quarter are. As a consequence, diverse neighborhoods contain a majority of voters in 33 of the state’s 40 legislative districts. In 19 districts, more than 80 percent of residents live in a diverse area. Political control of the state belongs to racially diverse and integrated communities, not to white suburbs. It is likely not a coincidence that the lawsuit has been unusually well received by many of the state’s legislative leaders.

That doesn’t mean new efforts at desegregation will be easy. Efficiently desegregating a large region can be a tricky policy problem, and the process of implementing a plan can be politically bumpy, rattling school officials. Montgomery County, Maryland, is encountering those very bumps right now as it considers school-boundary changes. Other suburban districts—like that of Eden Prairie, Minnesota, in 2010—have had to navigate angry parents and community meetings to pursue desegregation. Minimizing the burden of integration plans is important, because affluent neighborhoods may still object to being inconvenienced for the sake of someone else’s child, and polls consistently show that white parents remain skeptical of making major trade-offs for racial diversity. Sharing the cost and time burden of school integration has always been a sticking point for policy makers.

That said, controversies can be overcome with a little political resolve. Eden Prairie ultimately approved its integrative boundary changes, and remains racially balanced to this day. Desegregation didn’t roil the nation because it was inconvenient, but because it touched a racial live wire that ran down the middle of America’s urban-suburban divide. It’s worth remembering that historical busing often put the burden of traveling to distant schools on black students, which made transportation-based schemes more controversial in black communities than other desegregation methods. Despite this, the practice polled much better among black Americans than among white Americans—usually receiving majority support, including in polls as recently as last May. Although there have recently been a few high-profile cases of Asian-American-led groups challenging affirmative-action programs, those polls also suggest Asian and Hispanic families are neutral on busing, with the latter overwhelmingly favoring government-supported integration. Instead, the beating heart of busing resistance was invariably all-white suburbs that received the bused children, where it was opposed by 50-point margins or greater.

By every available demographic metric, those white suburbs are losing ground in 21st-century America. The problem of segregated schools, as urgent and familiar as ever, is embedded in a deeply unfamiliar context. School integration in 2019 means moving children across racial boundaries that are already looking ragged. The communities it risks outraging have ever-shrinking political clout. People should consider whether they have overlearned the lessons of history—whether the antibusing consensus is more robust than the conditions that created it. Integrated schools are more achievable than the political system believes. The missing ingredient for desegregation may just be elected officials with the courage to stop fearing America as it was, and start leading America as it is.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.