College sets stiff test for failing Bush: John Lichfield in Washington on the hidden battleground in the closest US election since 1976

THE WORLD'S oldest think-tank, the Brookings Institution, ran a model of the American presidential election through a computer last week. The program was first tried four years ago, when Michael Dukakis was 17 points ahead in the opinion polls. The computer stubbornly predicted a handsome victory for George Bush at between 52 and 53 per cent of the popular vote. Come November, Mr Bush won with 52.7 per cent.

The equivalent information for this year's campaign was fed into the Brookings model over the last few days - second-quarter economic figures, candidates' poll ratings and a complex set of variables based on the 'ennui' factor - how long a party has continuously occupied the White House. The computer forecast that Bill Clinton would win with 51 per cent of the nationwide vote.

Whatever one thinks of computer models - another forecasts a narrow victory for Mr Bush - the Brookings figures echo the consensus view of thinkers, pundits and strategists in both parties. This will be the closest election since Jimmy Carter's narrow win in 1976.

The closer the election, the more the geographical politics of America - and the distorting effect of that mysterious entity, the electoral college - will come into play. Even with Mr Clinton 20 to 30 points ahead in the polls and the Bush campaign floundering, geographical politics is one reason why the more cool-headed Republicans are not panicking - at any rate, not yet.

The electoral college is the phantom second stage of the US presidential election. In each state a candidate wins, even by a handful of votes, he scoops all the votes in the electoral college: 54 this year for the largest state, California, three for the smallest in population, such as Wyoming and Alaska. The candidate who wins enough states to assemble a simple majority of votes in the electoral college - 270 is the magic number - occupies the White House.

In the 1970s and 1980s, apart from the Carter victory, Republicans achieved a crushing regional domination in presidential politics. To their traditional bastions in the mountains and plains they added the whole of the former Democrat empire in the South. Republicans entering a presidential race in the past two decades could take huge swathes of the country almost for granted. The Democrats, by contrast, had practically no states in which they were assured of victory, save Minnesota and the District of Columbia.

Over the last five elections, 'bedrock' Republican states, where an average of at least 55 per cent of voters have supported the party, have been worth 205 of the 270 votes needed for a majority. The 'bedrock' Democratic vote has been worth three votes.

While Ross Perot was in this year's race, splitting the moderate-to-conservative vote, this stranglehold - the so-called 'Republican Lock' - was broken. With Mr Perot out, Mr Bush begins the 1992 race - psychologically and tactically - on the third lap of a four-lap race.

Any candidate who wins the nationwide vote, even with just over 50 per cent, is almost certain to win enough states, large and small, to put together an electoral college majority. But because regional differences still exist and the US consists not of states but of 'media markets', Republicans start with an invaluable tactical and pyschological advantage.

In 1988 the Democrats had to concentrate their resources in a group of large swing states: California, Illinois, Ohio, Michigan and Pennsylvania. To have any serious chance of winning, Mr Dukakis had to win all of them. The Republicans could shovel resources into the same states, knowing that they need only win a couple of them to deny the Democrats victory.

One Republican strategist said: 'It is like a game of chess in which one player, though having roughly the same pieces, is pinned in a corner of the board and his opponent has all the choice of moves.'

This year, the Democrats hope that Mr Clinton, their first Southern nominee since Mr Carter, will be able to break the blockade and broaden out the board a little. With Mr Perot out of the game, Mr Clinton's hopes of a big breakthrough in the South, such as winning Texas or Florida, are dimmed. But the Democrat candidate and his running-mate, Al Gore, should be able to hold their home states of Arkansas and Tennessee. And party strategists say their polling shows that a South- South Democratic ticket makes a clutch of other Southern states - Louisiana, Kentucky, Georgia, possibly North Carolina - at least marginal enough to throw the Republicans off balance.

California looks pretty safe for Mr Clinton. Demographic changes and a young, moderate Democratic ticket make Colorado and maybe New Mexico winnable for the first time in more than 40 years. As always, the fiercest battleground will be the industrial Midwest - Illinois, Michigan and Ohio. But, unlike in past years, Mr Clinton can threaten to assemble an electoral college majority without having to win all three states.

----------------------------------------------------------------- TOP TEN STATES BY ELECTORAL COLLEGE VOTES ----------------------------------------------------------------- Of the 538 total votes:- State No of votes 1 California 54 2 New York 33 3 Texas 32 4 Florida 25 5 Pennsylvania 23 6 Illinois 22 7 Ohio 18 8 Michigan 18 9 New Jersey 15 10 North Carolina 14 -----------------------------------------------------------------