Millions of Americans go to the polls to elect a president tomorrow - but while some of them have been courted by both candidates, other have been largely ignored. Nick Morrison reports.

IF you were a voter in Toledo, Ohio, over the last six months you would have been exposed to more than 14,000 TV commercials angling for your vote. If you were a voter in California or Texas, you would be hard pressed now to find one, even if you wanted to.

Such is the US electoral system: a small number of votes in a small number of states will determine who is to become the most powerful man on the planet for the next four years.

It was as recently as 1984 that Ronald Reagan almost swept the board, winning every state except Montana, the home state of his Democrat opponent Walter Mondale. But recent races have been much tighter affairs and have come down to the result in the "battleground" states.

Each state sends a certain number of electors, broadly based on its population, to the Electoral College. Whoever wins the most votes in each state, gets all of that state's Electoral College votes (although Maine and Nebraska are exceptions). Whoever has the most votes in the Electoral College, becomes president.

So the target for both George Bush and John Kerry is to win more than 50 per cent of the votes in each state. Once that has been achieved, all additional votes are meaningless - there is no benefit in winning a state by a wide margin.

With many of the states clearly leaning towards one or other of the candidates, the focus turns to those states which could go either way, the battleground states.

But even the number of battlegrounds is dwindling. It was once thought to comprise 20 states, now it is just about a dozen, with some commentators putting it at even fewer than that.

And even among these swing states, there is a clear pecking order. Florida, Ohio and Pennsylvania are the most sought-after, accounting for 68 electoral college votes between them. But even the smaller states can prove crucial: in 2000 George Bush secured 271 Electoral College votes, one more than the winning threshold and five more than Democrat Al Gore. Had Gore taken West Virginia last time around, where Democrats outnumber Republicans two to one, he would now be the one seeking re-election.

But just as the national polls put the race too close to call, so the result in some individual states is likely to go to the wire.

Last time it was Florida and its "hanging chads" which decided the result, Bush winning the state of six million voters by just 500 votes. It took several recounts and a dispute over whether a vote counted if the hole had not been fully punched through the ballot paper, leaving a "chad", before victory could be proclaimed.

But other states were equally close. Gore won Iowa by 5,000 votes, Wisconsin by 5,708 and New Mexico by 366, and any of these three could fall to Bush this time.

Population changes mean if Bush were to win the same 30 states as last time, he would win 278 Electoral College votes, compared with 271 last time, but if Kerry were to hang on to Gore's states and take either Florida or Ohio, he would be in the White House.

Florida, where Bush's brother Jeb is governor, may seem a tough nut to crack, but the Democrats have been working on increasing turn-out among black voters, playing on the resentment over the 2000 election.

Ohio is a talisman state: no Republican has ever lost there and still been elected, and the Bush campaign has been particularly assiduous in courting the Amish population, which numbers 55,000, by emphasising the president's opposition to abortion and gay marriage.

If Kerry fails to win either Florida or Ohio, his hopes seem doomed, with not enough votes in the remaining target states to swing victory. And the Democrat also faces a fight to hang onto some of the states Gore won in 2000, with Iowa, Wisconsin and Minnesota all on Bush's hit-list.

Missouri has traditionally been the ultimate swing state, voting for every winning candidate in the 20th century except Dwight Eisenhower in 1956, although with Bush trailing this year it is starting to lose its battleground status.

One consequence of this amplified first-past-the-post system is that it is possible to lose the popular vote but still win the White House. Grover Cleveland lost out to Benjamin Harrison in 1888, even though he polled more votes, and George Bush won last time out despite winning 47.87 per cent of the vote to Gore's 48.38 per cent.

While the Electoral College system, introduced into the 1787 constitution to prevent larger states dominating smaller ones, at a time when the people were not trusted to directly elect the president themselves, gives California the largest number of votes, at 55, it is a solid Democrat state, and has been written off by Bush.

Similarly, Texas, with the second largest number of Electoral College votes, will vote for Bush, its former governor, in spades, and has been virtually ignored by the Kerry camp.

The result is that approximately 60 per cent of the American population have not seen a single presidential advertisement since March. The remaining 40 per cent are bombarded almost every time they turn on the television.

And the last week of the campaign has seen both candidates make repeated visits to those swing states, particularly in the Mid-West. At one rally in Ohio, Kerry joked that he was in the state so often he was thinking of getting his mail redirected there.

It can be dangerous to assume states are out of range. In 2000, early polls showed Gore trailing Bush by ten points in Ohio, the Democrat pulled out of the state in early October, and ended up losing by just 3.6 per cent. Needless to say, victory in Ohio would have put him in the Oval Office.

But in a race dominated by money, spending hard-earned campaign dollars in a state that is beyond reach is a waste, just as spending money in a state where victory is already assured.

With even the latest polls showing a significant proportion of voters are undecided, both candidates are sparing no quarter in appealing to the middle ground. To be an undecided voter in a swing state is to have a lot of power in the 2004 election.

But in a race too close to call, and the country as evenly divided as it was four years ago, there is every chance it could again be a disputed contest, and no guarantee that, once again, it won't be the courts which have the deciding vote.