Business English: Just who are we? America's middle class dilemma

Julián Castro, the 37-year-old mayor of San Antonio, claimed a special expertise before lecturing his fellow Democrats on how the American middle class could pull itself up by the bootstraps: his home state of Texas is one of the last places in the country where people would recognise a bootstrap if they saw one.

Mr Castro's own story of ascent into the American middle class began with his Mexican-born grandmother, who paid for his mother's stay in a maternity ward with Dollar300 won at a menudo cook-off. Most Americans are even less likely to recognise a bowl of menudo (a kind of cow stomach soup) than a bootstrap. No one eats it on Leave It to Beaver or Happy Days or The Cosby Show. The Democrats devoted their convention in North Carolina to solving a conundrum both parties face: they are desperate to identify themselves with the broad middle class of the US without a clear idea of how that middle class has changed.

We are told at every turn that the middle class is shrinking. Wouldn't a smart political tactician be better advised to identify the classes that are growing and win their allegiance? Not really. The middle class remains too big to ignore, mostly because it is not really a class. The British middle class was traditionally a small, discrete group of educated and fairly well-off people, lodged between the nobility and the gentry above and the workers below. When Americans say "middle class", they imagine someone right in the middle of the country's distribution of income and education and consider him as a general type.

  Joe Biden's wife described her husband and Barack Obama as seeking to strengthen "the middle class they grew up in"

A study by the Pew Research Center found that, as an objective matter, this group is indeed shrinking. In 1971, 61 per cent of Americans lived in households with between two-thirds and twice the median income. Now only 51 per cent do. But the tendency of Americans to identify themselves as middle class remains strong, and consistent across sociological groups: 51 per cent of whites see themselves this way, along with 48 per cent of blacks and 47 per cent of Hispanics. Hispanics have a slightly more modest idea of what constitutes "middle class" life. Blacks and whites say it takes about Dollar75,000 a year for a family of four; Hispanics put it at about Dollar50,000.

Moreover, each party claims to represent the middle class and to guard its values against the depredations of the other party: 94 per cent of Democrats say Republicans represent the rich; 74 per cent of Republicans say Democrats represent either the rich or the poor.

So Democrats sought to do two things on their party convention - to strengthen their identification with middle class voters and to expand the base of people who consider themselves as such. Jill Biden, wife of the vice-president, Joe Biden, described her husband and Barack Obama as seeking to strengthen "the middle class they grew up in", even though the president has said his own mother was on food stamps at one point. No matter: a new assumption in the convention oratory was that government assistance is no impediment to full membership of the middle class. The Iraq war veteran Tammy Duckworth, a congressional candidate, said: "Thank God for the food stamps, public education and Pell grants that helped me finish high school." An Obama campaign ad shows a man in a hard hat and a reflective vest, lifting a lunch pail out of a pickup truck - all symbols of traditional working class culture - as the narrator intones: "The middle class is carrying a heavy load in America ... "

One striking change among middle class voters is a reversal of the two parties' views of the future. Ever since Ronald Reagan won a thunderous re-election in 1984 by declaring it was "morning in America", Republicans have claimed the mantle of optimism while Democrats have been gloomier.

That has changed. Now 54 per cent of middle class Democrats think their children will enjoy a higher standard of living than they did, versus 31 per cent of middle class Republicans.

In his own speech, Mr Obama showed signs of his gift, familiar from the 2008 campaign, for couching the most progressive sentiments in almost reactionary-sounding language. He promised to "restore the values" that built such a large middle class in the first place. But this is not really a restoration. Mr Obama is betting that those values include a considerably bigger role for government than they did two or three decades ago. He may be on to something. When Pew asked self-identified members of the US middle class whom they blamed for their present economic predicament, they named, in the following order, the US Congress, banks, corporations, George W. Bush, globalisation, Mr Obama and (last of all) middle class people themselves. American voters appear to be as Mr Castro describes them: a people who have forgotten what a bootstrap is.