Click here to see what both parties are made of

EVEN in the thick of America’s congressional election battle, where there has been a steady barrage of opinion polls and headlines pointing to a Democrat triumph, the Republican high command remains remarkably calm.

Karl Rove, the architect of George Bush’s two presidential wins, has been busily telling anyone who will listen that he has total confidence that Republicans will retain control of not only the Senate but the House of Representatives on November 7.

This optimism, which even some colleagues fear may be foolhardy, is based on the edge that he believes Republicans still have on the ground as well as over the airwaves.

The media war is straightforward: Republicans have a $55 million (£29 million) advantage over the Democrats in what they can spend on blanket TV advertising in the closing three weeks. It will be ploughed into the tight races that will decide which party controls Congress.

Some analysts believe that the House of Representatives could be decided by as few as 300,000 voters out of a country of 300 million people in 30 districts. But it is in the ground war — in identifying, targeting and mobilising voters, all largely out of sight of the media — where Mr Rove hopes the election machine he has built over the past six years has perhaps the greatest capacity to confound the polls.

Traditionally, the Democrats had the upper hand in what used to be called “get out the vote” operations, partly because they were able to deluge urban areas where their support is most concentrated with volunteers and union activists.

But the narrow margin of Mr Bush’s victory in the 2000 presidential election, when Al Gore was defeated even though he had won a majority of the popular vote, left Mr Rove vowing to find a more scientific way of winkling out supporters than merely looking at street maps.

The Republicans invested about $20 million in 2000- 2002 building a system called Voter Vault. This is based on commercial programmes used by direct-mail advertisers that use consumer data to profile individual residents in each district. This was then reviewed and updated with information from direct contact with voters, enabling the Republicans to “microtarget” potential supporters with mailshots and canvass calls appealing to new sub- categories not usually regarded as voting blocks.

For instance, in Michigan during this campaign, Republicans have been contacting everyone who owns a snowmobile to suggest that the environmental views of Democrats stood in the way of their sport.

The technique was one reason why, in the 2004 election, Mr Bush increased his vote by 23 per cent.

According to Republican strategists, the biggest gains were made in traditionally Democratic wards where sympathetic voters had previously been ignored by the old system.

In some campaigns, Voter Vault was, for example, able to identify one family member opposed to abortion, allowing the party to microtarget people within the same household.

Nationally, this scalpel-precision allowed thin slivers of voters to be sliced off the Democrats and added to the Republican cause. Where it was used, strategists claimed that an increase in support of 10 per cent was achieved among evangelical Christians, 9 per cent among Hispanics, and 5 per cent from Catholics. But the Democrats have, at last, begun trying to catch up.

Karen Hicks, who helped to run field operations for John Kerry’s campaign in 2004, said that while the Republicans had the advantage of “building a new structure from scratch”, her party had been trying to “renovate an old system”. Although the Democrats had developed their own national computer file in 2004, nicknamed “Dem-zilla”, voter records were often controlled, and jealously guarded, by state parties or had been thrown away between elections.

Since then the Democratic National Committee has spent about $8 million building a file for six key states in this campaign. But the uncoordinated approach has continued with a group called Catalist creating its own system for special interest groups, while others are being developed for the Senate and the House campaign committees.

“It’s every man for himself,” said Donna Brazile, who managed Mr Gore’s 2000 presidential campaign. Ms Hicks was brought in as a consultant to work on Labour’s 2005 general election campaign, where she noted that the Tories had purchased Voter Vault from the Republicans — “although they didn’t really know how to make it work”. Labour and the Conservatives used a commercial programme called Mosaic, which placed Britons into categories such as “golden empty nester”, “small town senior”, “parochial villager”, or a “new urban adventurer”. But neither party had been effective at matching such clusters to local political data on voters’ intentions.

Although Ms Hicks has no doubt that such systems will be used more in the UK, she said that “building political infrastructure like this takes a lot of time”. She added: “This is a technique, not a complete strategy, and the Republicans cannot technique their way out of the current hole they are in: it is too big this time.”

Privately, some Republicans agree with her. One said: “Karl is still very upbeat and — even though I shouldn’t doubt him — I do.” The fabled Voter Vault may not be quite as full this year as it once was.

REASONS TO BE CHEERFUL
(if you’re a Republican)

Recent boundary changes mean that while Democrats may be way ahead in national polls, less than a tenth of Congressional seats are realistic targets

Times Recommends

• Michael Jackson: Not the final chapter
• Indian Army spends10m rupees on golf buggies
• Brüno toned down for 15 rating