The Republican candidate, Governor George Bush, was almost begging. "In the last days of this campaign, I need you all to work your neighbourhood and talk to your friends," he urged the Miami crowd on Sunday. "Turn out the vote."

In the past few days both he and Vice-President Gore have gone back to the heartlands, to their core voters in the key swing states, with the same message. Campaign managers have all but abandoned the idea of persuading voters to switch their allegiance or making inroads into the 10 per cent who still say they don't know how they will vote. The battle will be won by the party which turns out more of its traditional vote.

And yet in this country which prides itself on being the democratic model to the world, and after a tantalisingly close campaign costing parties and lobbies a record $3 billion, today one in two eligible voters will almost certainly stay at home.

And so the campaigns are using everything from e-mails to TV ads, to door canvassing to get them out. Record numbers of absentee ballots have already been sought and cast.

Since 1960 US voters have been less and less inclined to turn out. Then, in the bitter duel between Jack Kennedy and Richard Nixon some 63 per cent voted, a peak for the past 75 years. The vote had risen steadily from the 1920s - 48.9 per cent in 1924 - dipping sharply only in 1948, and then starting its 40-year decline, occasionally buoyed up by a close race.

In 1996 it was down to 49 per cent, less than one in two, but then, as many Democrats will tell you, President Bill Clinton was already looking like a certainty. But in the 1998 congressional elections as few as 36 per cent cast their ballots.

Democrats are pinning their hopes on the tight contest this time energising their somewhat more reluctant voter base to come out and upset pollsters' predictions. They have been using models based on a low turnout, models which the Democrats say underestimate their potential vote.

A New York Times/CBS poll yesterday makes their point - on a turnout of 45 per cent, 47 per cent were likely to vote Bush. As the turnout increases to 51 per cent, the Bush figure slips to 46 per cent, and if account is taken of all registered voters, it goes down to 45 per cent. Too close to call.

In the black community, the main centre-ground lobbying organisation for black people's rights, the National Association for the Advancement of Colored People, has been funding a massive $9 million ad campaign in a dozen swing states for the first time. For the Democrats this is a key area - 82 per cent of blacks who vote vote Democrat.

Registration and voting drives in Michigan have pushed black voter turnout up from 9 per cent in 1992, to 13 per cent in 1996 and 19 per cent in 1998. In Georgia similar drives brought the black turnout from 19 per cent in 1994 to 29 per cent in 1998. The result has been to bring black voters close to their share of the electorate and to enhance significantly Democratic chances - every 1 per cent increase in the share of voters represented by black voters is another 0.8 per cent for Al Gore.

Trade unions, environmental groups, abortion rights groups, right to life groups, gun lobbyists, the Christian Coalition, the Chambers of Commerce, are all involved in unprecedented moves to turn out thousands of volunteers to drum out supporters.

A recent study of non-voters' attitudes conducted by the Washing- ton Post and Harvard University shows what an uphill task they have. Some 35 per cent of non-voters, the study found, are completely apathetic about politics with little or no sense of social engagement or civic responsibility, a group that has been growing in size.

Another quarter of the non-voters, are angry, cynical and embittered with politics to the point of opting out. They look on all politicians as crooks, the system as fundamentally flawed, and are unlikely to be re-engaged.

Yet another group of a similar size, perhaps reachable by campaigners, say they are disenchanted by the way politics is practised and are not so much repelled by politics as by the form it takes, not least what they see as the partisanship of the Washington elite.

Surprisingly, perhaps, the survey finds little gender or racial difference in voting patterns but age and educational attainment are key indicators. Some 41 per cent of 18- to 30-year-olds are not registered to vote, compared to only 12 per cent of those over 61.

The Census Bureau reports that less than a third of 18- to 24-yearolds said they had voted in the last election. Among Hispanic men and women of that age the figures are as low as 12 per cent and 18 per cent respectively. And yet 70 per cent of 64- to 74-year-olds vote.

The decline in the youth vote is not new - half of them voted in 1972, and 41 per cent in 1984. Little wonder when 70 per cent of the same age group say that the election either won't affect them at all or will have only a small impact, and half will come up with "don't know" when asked to name the most important issue to them not being discussed by the candidates.

Participation rises with educational attainment, with non-registration declining from 43 per cent among those without a high school degree to 14 per cent among college graduates.

The difference in participation rates between rich and poor is also dramatic. While only half of all adults in households earning $25,000 or less vote, the same is true of three-quarters of adults in households earning $75,000 or more.

Such differences in behaviour are unparalleled elsewhere. "In other Western democracies there's maybe a 5 per cent difference in voting between those at the bottom and the top of the ladder," Mr Thomas Patterson, one of the Harvard team says.

Unlike youth abstentions, which tend to be politically evenly spread, such abstentions by the poor make an important difference to the voting outcome. Voters earning less than $15,000 a year are likely to split 53-26 in favour of Gore while those earning over $75,000 a year split 52-41 in favour of Bush.

And the Harvard survey found that voters favour using the country's budget surplus to cut taxes by a 2-1 margin over non-voters. Forty-five per cent of non-voters want the surplus spent on improving health and education. But who listens to the non-voters?