In July last year, the weekend John F Kennedy Jr's plane went missing near Martha's Vineyard, his magazine, George, devoted its cover story to the growing Hispanic influence on mainstream American culture and politics. For Kennedy's magazine - whose slogan was "Not just politics as usual" - the US was becoming the new Latin America, with millions of Latinos poised to tip the balance at the next presidential election. It featured several profiles of Latino success stories (mostly actors, entrepreneurs and establishment politicians) and a small strip down the side of each page with bite-sized highlights of the history of Latinos in the US - from the Alamo to the moment, in 1991, when Mexican salsa surpassed ketchup as America's favourite condiment.
The piece was typical of several recent articles in US magazines which have grappled with the truth that, within the next 50 years, Latinos - or Hispanics, as they are referred to in the US census - will outstrip blacks as the biggest minority, and that whites themselves will then become a minority, a phenomenon that has hardly registered in Britain. Three years ago, I made a radio documentary about a week in the life of Miami airport, in an attempt to show how much the city is a northern hub for Latin Ameri-ca. I was amazed to discover how surprising it was to many people in London that you often hear more Spanish than English being spoken in shops and diners in Coconut Grove or Coral Gables. (Anglos, as white people are commonly called in Miami, are infuriated when the pleasure of eavesdropping on exchanges of scandalous gossip is ruined by abrupt switches from English to Spanish at the juiciest junctures.)
Such surprise is not confined to the English. White Americans who have not been to the big cities where the Latino presence is most visible are similarly shocked when they pass through Miami. Three oil workers from Illinois, on their way to a job in Venezuela, whispered "This is not Ameri-ca!" as they passed through the crowded airport concourse. It was hard to tell whether they were awestruck or repulsed. The idea that "spics" are given to laziness, cruelty and corruption has deep roots in US mythology; it is a historical transposition of the low regard that the British bestowed on Spaniards from the 16th century onward, and is doubly applicable to "half-breeds" - as are most Latinos. Today, such caricatures may not be as crude, but it is a fair bet that, for many white Americans of insular disposition, the answer to being surrounded by maids, gardeners and window cleaners from Latin America is to act as if they are invisible. Hence, in mainstream magazines, the only way to draw attention to the Latino population explosion is to write about entrepreneurs and celebrities.
This approach is not for Mike Davis, whose book on Los Angeles, City of Quartz, did for geography what Raymond Chandler did for genre fiction. Learned and polemical, Magical Urban-ism is the best serious guide on the market to the rise of Latino Americans. In one arresting passage, Davis likens the barricade erected along the southern border of the US to a dam that creates a reservoir of labour on the Mexican side, ready to be tapped on demand via "a secret aqueduct" of people-smugglers and service sweatshops, farms and hotels.
Davis begins with the obligatory demographic summary: in six of the ten biggest cities, Latinos outnumber blacks; the Spanish surname population is increasing ten times faster than Anglo surnames; the majority of people arrested during the LA riots in 1992 had Latino surnames. But one of Davis's most telling observations about the changes of the past 30 years is that the town where Richard Nixon studied, Whittier - once the epitome of white American Main Street - has been transformed by Mexican-American art dealers and booksellers into a Latino version of Greenwich Village. Davis argues that, because most Latinos live in cities, they may help to restore life to urban spaces, acting like "a dynamo turning the lights back on in the dead spaces of North American cities".
But there is little pay-off for enterprise: those Latinos reinvigorating downtown Los Angeles do not receive the same subsidies as those lavished on the white middle class for gentrification. Local administrations in the big cities have no money to spend, so Latinos don't have the same incentive to participate in politics as Jewish and Irish immigrants did in the early part of the 20th century. With most Latinos not registering or not bothering to vote, the initiative in areas such as California lies with the rich, who are busily splitting off their prosperous enclaves from poor or lower-middle-class neighbourhoods, replicating the social geography of Latin Ameri-can cities to the south. As a result, Latino political leaders fight with blacks over the diminishing spoils and, in the process, sunder alliances such as the Rainbow Coalition.
There is, too, the age-old problem that Latinos do not constitute a cohesive group. Cubans run Miami, but poor Nicaraguans are excluded; the Mexicans have more clout in LA than Salvadorians. The most contentious part of Davis's argument is his utopian belief that these obstacles are about to be overcome, and that Latinos are engaged in a "unique process of cultural syncretism that may become a transformative template for the whole society". This is not entirely convincing, although I suppose it is as good a starting point as any. And, some day soon, the British idea of the US as a history of white and black will have to change. Magical Urbanism is the most informative first step to that enlightenment.
Maurice Walsh is a BBC journalist