A nation of 50 states, but only a dozen will affect election

The United States consists of 50 states and the District of Columbia. But the outcome of the presidential election on 2 November will hinge on a dozen or fewer of them, the so-called "swing" or "battleground" states where George Bush and John Kerry are now spending almost all their time, and most of their advertising money.

The United States consists of 50 states and the District of Columbia. But the outcome of the presidential election on 2 November will hinge on a dozen or fewer of them, the so-called "swing" or "battleground" states where George Bush and John Kerry are now spending almost all their time, and most of their advertising money.

Even in an election as closely fought as this one, about 30 states are tacitly conceded by one side or the other, under the winner takes-all-system of the electoral college.

Except in a potential landslide year, a Republican is wasting his time in California, New York, Illinois and other north-eastern states.

Similarly - again barring a landslide - the Democrats will lose most states in the old South, the great plains and the Rocky Mountains. The wider contest boils down to about 20 states. But as election day approaches, that number shrinks even further.

The precise classification of these battleground states varies from day to day, from poll to poll, and according to the candidates' travel schedules. But eight are on everyone's list, led by the "Big Three" of Ohio, Pennsylvania and Florida, the biggest prize.

This trio represents a quarter of 270 electoral votes needed to win. The conventional wisdom is that the candidate who carries two of them will win the White House.

At the end of election day, experts suspect, Ohio and Pennsylvania will break as they did in 2000, the former again for Mr Bush and the latter for the Democratic candidate (then Al Gore, now Mr Kerry). Which produces that familiar sinking feeling: not Florida again?

Thanks to the two extra congressional districts awarded it after the 2000 census, Florida this year carries even more weight than when Mr Bush won it by just 537 votes, or 0.0001 per cent of the popular vote in the state.

Indeed, the overall reweighting of electoral votes to take account of the population shift to the south and west, means that Mr Kerry has a significantly harder task than Mr Gore.

Assuming every state votes as it did then, Mr Bush would win by 278 to 260, a margin of 18 votes in the 538-vote electoral college, compared with his 271-267 victory four years ago.

But Florida, Pennslyvania and Ohio are not the only games in town. This time around, a new group of states in the upper Mid-west - Wisconsin, Minnesota and Iowa - are scarcely less crucial. Not so long ago, these latter states were reliably Democratic. But Republicans have made steady progress in recent elections.

In 2000 for instance, Mr Gore carried Iowa by barely 4,000 of 1.3 million votes cast. This year the three, with 28 electoral college votes between them, are toss-ups. If he loses all three, it is hard to see how Mr Kerry wins the White House.

Completing the list of the most closely contested states are New Hampshire (won by Mr Bush in 2000) and New Mexico (carried by Mr Gore by just 365 votes). Not surprisingly the advertising is concentrated in these states as well.

Miami, Orlando and Tampa in Florida are among the top 10 advertising cities for either Republicans or Democrats. So are three cities in Ohio, Columbus, Cincinnati and Cleveland.

Albuquerque in New Mexico and Green Bay, Wisconsin, are also among the top 10 for both parties. Beyond the inner eight are a dozen or so states where the outcome is not certain, but which are tilting towards one candidate.

This category includes Washington, Oregon, Maine and New Jersey, all leaning towards Mr Kerry.

Those which Mr Bush is likely, but not certain, to carry include Nevada, Arizona, Colorado, Missouri, Arkansas, Louisiana, West Virginia, Virginia and Tennessee.