A wary but tenacious middle class is fast becoming the majority in Mexico, breaking down the rich-poor divide in a profound demographic transformation that has far-reaching implications here and in the United States.

Although many Mexicans and their neighbors to the north still imagine a country of downtrodden masses dominated by a wealthy elite, the swelling ranks of the middle class are crowding new Wal-Marts, driving Nissan sedans and maxing out their Banamex credit cards.

The members of this class are not worried about getting enough to eat. They’re worried that their kids are eating too much.

“As hard as it is for many of us to accept, Mexico is now a middle-class country, which means we don’t have any excuse anymore. We have to start acting like a middle-class country,” said Luis de la Calle, an economist, former undersecretary of trade in the Mexican government and the co-author of a new report called “Mexico: A Middle Class Society, Poor No More, Developed Not Yet.”

The stereotype is no longer an illegal immigrant hustling for day labor outside a Home Depot in Phoenix. The new Mexican is the overscheduled soccer dad shopping for a barbecue grill inside a Home Depot in booming Mexican cities like Queretaro.

When President Felipe Calderon of the center-right National Action Party won in 2006, outpolling the leftist Mexico City Mayor Andres Manuel Lopez Obrador, it was the middle class that gave Calderon his wafer-thin victory.

And in the presidential election in July, Mexico’s growing economic center will again be decisive, say political analysts from all three major parties.

The Mexican middle class is heterogeneous, anxious and divided among the major political parties; its members are socially moderate but fiscally conservative, cynical about political promises and fearful that recent gains could be lost in a financial crisis or social upheaval — the kind that buffeted Mexico in the 1990s.

“The middle class in this country doesn’t want to lose what it’s gained,” said Gabriel Paulin, 30, living in a mod condo in a new subdivision in Queretaro. On his coffee table: a Spanish-language copy of Ayn Rand’s “The Fountainhead” — essential reading for the striving class — alongside a boxed DVD set of the “Mad Men” television series.

Mexico’s middle class thrives here in the country’s central highlands, in buzzing industrial cities that bear little resemblance to the violent border towns of the Rio Grande or tourist magnets such as Cancun.

In Queretaro, a sunny, fastidious state capital of a million residents two hours north of Mexico City, new subdivisions and industrial parks are sprouting across the cactus lands, welcoming waves of aspiring Mexican families drawn by job opportunities and safe neighborhoods.

Some of the newcomers have fled the drug violence of cities farther north, such as Monterrey, where middle-class Mexicans feel increasingly vulnerable to kidnappers, extortionists and random killings — the Mexico they are eager to leave behind.

By comparison, Queretaro is a haven of relative calm. The homicide rate here is on par with Wisconsin, about 3.2 per 100,000 residents.

It is in sunny Queretaro where you can clearly see the new Mexico of 60-hour workweeks, Costco box stores and private English-language academies churning out bilingual 14-year-olds.

It is the Mexico where the top 50 names for newborns include a lot of American-sounding names such as Vanessa and Jonathan, where people pay $5 for movie tickets at the cineplex and the public tennis courts have a waiting list.

And it is the Mexico where NAFTA dreams came true, where billions in foreign investment have fostered a flourishing aircraft-manufacturing industry anchored by companies such as Bombardier Aerospace, General Electric and Siemens.

On Queretaro’s eastern edge, developers are building a planned community from scratch, a middle-class burb-topia called “Zibata” (a made-up word) designed for 150,000 people.

Zibata will be a gated community — a gated city — with security checkpoints that use facial-recognition software to determine who can enter. But its target demographic is not the wealthy — it’s the middle class, said Zibata pitchman Miguel Vega, pointing to a scale model showing entire neighborhoods of modestly priced apartments and townhouses among bicycle paths, greenbelts and retail plazas.

“This is an inclusive community, not an exclusive one,” he said. “We’re trying to make high standards of living accessible to everyone.”

Vega said nothing symbolizes this impulse more than Zibata’s most revealing idea: a planned 18-hole, par-72 public golf course, aimed at Mexico’s upwardly mobile, with a dedicated golf academy on-site to teach the swing fundamentals to future duffers.

Off the links, Zibata plans classes in deportment and civility, and the posting of lots of rules — about curbing pets, making noise and taking out recyclables — the kind of social mores local governments in Mexico rarely bother to enforce.

The advertising slogan for Zibata is “where the impossible . . . is possible.”

“It is what Mexicans want,” Vega said.

Hard to measure

The exact size and shape of this new class of home buyer is hard to measure. Counting the middle class in Mexico (pop. 114 million) is not a straightforward calculation as it is in the United States, where a 1040 tax return and a Zip code define who’s who on the economic scale.

In the developing world, in countries such as India, China and Mexico, scholars argue, the middle class can be defined by what its members consume, and so a Mexican homeowning household with a new refrigerator, a car and a couple of cellphones is considered middle-class — even if the combined salaries of the members of the household would make them miserably poor in Washington.

Another measure is perception: You are middle-class if you think you are middle-class. A February survey of Mexicans by the independent pollster Jorge Buendia reports that 65 percent of respondents consider themselves in the middle (27 percent described themselves as lower class, and only 2 percent copped to upper-class status).

“If you just look in someone’s wallet, Mexico is not growing that fast,” said Willy Azarcoya, founder of a small marketing research firm here, referring to Mexico’s steady but unspectacular annual GDP growth of 2 or 3 percent.

“But people think they can achieve things now, and that is the difference,” Azarcoya said. “It is an attitude adjustment.”

Azarcoya acknowledged that Mexico still harbors a huge number of poor — between a fourth and half the population, depending on the measures (food security vs. ability to buy needed household goods). Poverty ticked upward slightly after the 2008 global recession, but Mexico’s middle-class march is back on track, and the broader trajectory shows a steady climb out of mass poverty.

Azarcoya’s morning routine is not unusual. He gets up early. His wife works. Women represent 45 percent of the labor force. He drives the kids through rush-hour traffic to two private schools. There are now more than 20 million cars on Mexican roads, up from from 4 million in 1980. He reads e-mails on his iPhone while gulping a yogurt for breakfast.

When one of his clients, the cereal giant Kellogg’s, wanted Azarcoya to gather a dozen families for an advertisement showing them eating breakfast together at home, he had trouble finding them.

“Nobody lives like that anymore,” he said. “They want to live like that. But they don’t.”

Trend of smaller families

Smaller families are a hallmark of the growing middle class. In 1960, Mexico’s fertility rate was 7.3 children per woman, according to World Bank figures. Today, it’s 2.3, slightly above the U.S. rate of 2.1.

“My friends think we’re crazy for having three kids,” Azarcoya said. “Nobody has three anymore.”

Mela Ruiz, 30, who is expecting her first child in a couple of months, said she and her husband plan to have no more than two. The young couple own three small businesses — including her manicure shop, a franchise operation called “Spa Manos,” that Ruiz runs six days a week in a mall adjacent to a new subdivision.

“Going to college was expensive for me, so it’s going to cost even more in the future,” Ruiz said. “I want to be able to give my children the same things I had.”

Ruiz is not unusual, either. Since 1980, the number of Mexicans receiving a university education has tripled, according to the Organization for Economic Cooperation and Development (OECD). Private for-profit universities, with relatively affordable tuitions, are flourishing, such as TecMilenio, with 40 campuses across Mexico, that offer students the option of taking classes via the Internet.

“Those of us in the middle are the engine for progress in this country,” said Paulin, the “Mad Men” fan. “The rich? They’ve already got it made,” he said.

Paulin went to college, got an MBA and moved back to Queretaro for the job as a sales manager at a company that makes industrial disinfectants for Mexican agribusiness — mostly farms that export to the United States. Parked outside was his brand-new Mitsubishi pickup. He said a salary for his position is about $31,000 a year.

“There are good opportunities here,” he said. “There’s no reason to go abroad in search of a better life.”

Road to getting ahead

Although blue-collar Mexicans may continue to look north for job opportunities in manual labor markets such as farming and construction, a growing pool of professional and service workers see few reasons to go abroad, researchers say. They see a road to getting ahead right at home.

It’s a path paved with plastic for more and more Mexicans. The number of credit cards in circulation nearly quadrupled between 2002 and 2009, according to Mexico’s Central Bank, but debt leaves many Mexicans sensing that their foothold in the middle class is slippery.

“You may be middle class, but you still feel poor,” said Oscar Marquez, a 33-year-old father who has worked 10 years for Telcel, the phone giant controlled by Mexican tycoon Carlos Slim, ranked by Forbes as the world's richest man.

A good salary at Telcel is about $1,000 to $1,500 a month, Marquez said, enough for today but maybe not tomorrow.

“We live well, but it’s living well day to day. My wife wants me to set aside $100 a month for our savings,” he said. “But I’ve got car payments to make.”