NEAR THE BACK wall of a disused electronics superstore in Antioch, a suburb of Nashville, Tennessee, a Mexican flag on a pole is the only tangible sign that, for four days at least, this echoing space has become an outpost of the Mexican state. Though there is no sign on the door, this is a touring “consulate on wheels”, staffed by Mexican consuls based in Atlanta. The mobile team covers three states in the Deep South, reaching migrants who need to renew documents, register births and so on. On a typical day the mobile team’s high-security printers might spit out 200 passports.

On a recent winter morning the quiet hum of consular work is interrupted by angry shouts. “Who’s in charge here? What’s going on?” asks an old man in a camouflage fleece and hat. A local resident, he has been drawn by the sight of Hispanic families converging on a semi-defunct shopping mall and lining up for appointments with Latino officials. The Mexican consul in charge hurries to intercept him, saying soothingly that the site is providing a “community service”. Eventually the old Tennessean stalks out, his expression thunderous.

The scene is not mystifying to readers of Ronald Brownstein’s essay “The Gray and the Brown” and other studies of the demographic gulf opening between America’s mostly white old folk and its increasingly multi-hued children. Generational clashes are hard enough to deal with in homogeneous societies; harder still in a country where many youngsters look different, and are linked by the public with decades of illegal migration.

A common response is an appeal to cool rationality. Other advanced economies in the West, the argument runs, are already ageing and shrinking and societies are becoming timid, peevish and introspective. America is lucky to have millions of energetic young people filling its schools with kids who will eventually pay taxes and fund pensions and health care for the old. This makes a lot of sense. Mayors have been saying it for some time, having seen cities with declining populations entering a spiral of falling tax revenues, half-empty schools and dying neighbourhoods. Santa Fe, the pretty New Mexican city co-founded by the Salazar family, has managed to attract lots of affluent baby-boomers with an arty bent. But more than half the workforce is over 55, says its mayor, Javier Gonzalez. One of his winning campaign slogans was: “We have to dare to grow young.”

Yet in politics, rational arguments are not always enough. Happily, there is also a more emotional reason for anxious baby-boomers to welcome the rise of Hispanic-Americans. If older Americans are dismayed by how society is changing as traditional families grow weaker and neighbourhood bonds wither, then Latinos are their cultural allies. Arnulfo Olazaran Valladares, a carpenter waiting to renew a passport at Antioch’s consulate on wheels, has lived in Nashville since 1995. His eldest son is studying medicine in eastern Tennessee, thanks to a scholarship. Another son is an American citizen, which will allow Mr Valladares and his wife to apply for the deportation relief announced by Mr Obama in November last year but now mired in Republican-initiated lawsuits. Having papers would help the couple “drive without fear, have a better-paid job and have health insurance”, they say. These are hardly subversive ambitions.

Never before in American history has such a large group of new arrivals lived so close to their ancestral homelands

There is a lot that is not subversive about the Hispanic immigration wave that lasted from the 1970s to the financial crash in 2008—if critics can look past the original sin committed by those who arrived unlawfully (or in many cases arrived on legal visas, then overstayed). Unbidden, Hispanics often talk about how old-fashioned they feel in America, with their strong family ties, their churchgoing habits and (less happily) the dinner-table rows with their American-educated children. Like other immigrants, they talk a lot about the American Dream. By that they mean the baby-boomers’ hopes of home-ownership, a college education and upward mobility. Mr Falco, the staunchly Republican CEO of the Univision TV network, wishes that older, conservative Americans would see that Hispanics are kindred spirits. Polls back him up. Hispanics are more likely than the average American to say that getting a college education is integral to the American dream, and more likely to agree with a quintessential statement of American optimism, that “most people who want to get ahead can make it if they’re willing to work hard.”

The bad old days

Immigration sceptics are right that deliberate policy changes, pushed by Democrats under President Lyndon Johnson, led directly to an unprecedented increase in Hispanic immigration from 1965 onwards. To simplify, a decades-old bracero scheme that admitted Mexican men as temporary labourers, was scrapped in favour of immigration laws that encouraged migrants to make new lives in America and to bring their families. The new laws triggered a cascade of unintended consequences, with millions of families arriving to settle. Meanwhile low-income workers, finding legal paths closed to them, came anyway. Including illegal immigrants, perhaps 30m new residents arrived over 40 years, of whom a third were Mexicans.

All this appals many conservatives, who would like to see the bracero programme brought back and family migration severely curbed. But the bracero scheme was rife with bullying abuses and made no attempt to encourage assimilation. The immigrant laws scrapped in 1965 were equally hard to defend, with quotas dating back to the 1920s that discriminated against Jews and migrants from poor parts of Europe, Asia and Africa.

In 1958, before becoming president, John F. Kennedy wrote “A Nation of Immigrants”, a plea for an immigration debate worthy of America’s confident, welcoming traditions. Kennedy noted that the Declaration of Independence itself includes a complaint that King George III was restricting immigration. The British monarch would not allow “the naturalisation of foreigners” or “encourage their migrations” to America.

José Gomez, the Roman Catholic Archbishop of Los Angeles, wishes that Kennedy’s treatise were better known today. He has just one, mild, complaint: that the book’s account of American history begins in 1607, with Englishmen building a settlement in Virginia, and without a word about the Spaniards who first reached Florida in the 1520s. The archbishop, himself a naturalised immigrant born in Mexico, does not deny that Anglo-Protestant ideas informed America’s founding. But he ventures that 21st-century America sometimes feels a little too individualistic, to the point of loneliness, notably for the old. “The Anglo-Saxon mentality and the Latino, if we put [them] together and make it work, it is just the ideal combination,” he suggests.

Hispanics can be expected to maintain elements of their culture longer than migrants of previous centuries. Never before in American history has such a large group of new arrivals lived so close to their ancestral homelands, bound by proximity, language, a single time zone, cheap telecommunications and easy air travel. But Americans should have more confidence in their melting pot and its ability to soften once sharp distinctions between immigrant groups. The census projection that the Hispanic population will double to 100m by mid-century does not mean that today’s community will simply be cloned to make it twice as large. The power of the American market to reshape tastes and habits and break down barriers can already be seen in fields ranging from Christian worship to pop music. If current trends continue, many Latinos will marry out.

Those who welcome Hispanics must do so with their eyes open. The community suffers many ills. But that in part reflects its socio-economic situation. In many cities, Latinos are the backbone of the working class. With luck and goodwill, education and economic opportunity, they can be helped to avoid becoming an underclass. More of them will enter the middle classes. Fears that Hispanics are doomed by culture and numbers to import the troubles of their home countries are overblown, just as they were when earlier waves of Italian and Irish migrants caused alarm. People do not leave their countries to reproduce the pathologies they left behind. America is hardly alone among rich countries in having uneasy debates about immigration. But it does seem uniquely lucky. At a time when many western European countries as well as Japan are greying and ageing and fretting about where to find future workers, America is receiving a giant dose of youth and energy from close neighbours. So far, Hispanic voters have hardly made their presence felt. But they will, and in a democracy suffering from excessive partisanship, many of them look like swing voters. Rigid ideology has often hurt Hispanics, as hardline conservatives denounce any immigration reform that could be called an “amnesty”, while left-wingers demand a blanket right of citizenship for all those without papers. In truth, many Hispanics would settle for legal residency for the first generation of undocumented arrivals. The stubbornness of activists holding out for full citizenship probably derailed earlier bipartisan attempts at comprehensive immigration reform. Matt Barreto, of the pollsters Latino Decisions, explains that the Hispanic electorate is well-balanced. It is more religious than the rest of the country, he concedes, but dislikes religious leaders weighing in on politics from the pulpit. It admires hard work but reveres the solidarity provided by a community. It supports “pull yourself up by your bootstraps, but not as an organising principle for politics”, he concludes.

America’s white majority is turning into a minority, and tens of millions of American-born Hispanics will play a big part in that. The hope is that Latinos will enter, enrich and rejuvenate the American mainstream. Whatever happens, the mainstream itself will look very different. Americans must make this experiment succeed. There are many grounds for optimism.