By Adam Brookes
BBC News, North Carolina
North Carolina - no matter which way it votes on 4 November - is already an electoral surprise.
John McCain was in North Carolina on Monday to rally support
George W Bush won the state in 2004 by 12% - a huge margin. North Carolinians have not voted for a Democratic presidential candidate since 1976.
Yet, if we believe the polls, Barack Obama is now running neck and neck with John McCain. Pollster.com, which calculates an average of local polling results, puts Mr Obama at 47.9% and Mr McCain at 47.2%.
Those numbers strongly suggest that the Democrats have gained a lot of support in North Carolina. And they are forcing the Republicans to spend time and money defending a state where many assumed McCain would win easily.
So how did reliably conservative North Carolina suddenly become a battleground?
Shaving the voters
Demographics are important. The last few years have seen an influx of urban professionals into new technology centres in the cities of Raleigh and Durham. Charlotte's growth into a financial centre has attracted them, too, and many will be Democrats.
North Carolinians, conservative as they may be by history and temperament, are not immune to disillusion with the Bush administration, either.
But if you ask the Obama campaign staff, they will tell you - in that cool, slightly secretive tone that they seem to adopt with the press - that their local campaign organisation is the magic ingredient.
A visit to the No Grease Barber's Shop on the outskirts of Charlotte, North Carolina, gives a sense of what they mean.
The owners, Damian and Jermaine Johnson, with the Obama campaign's encouragement, have been registering voters for the past year at their three shops.
After every haircut and shave, customers are asked if they are registered to vote. If not, they are handed the registration forms.
Damian estimates he has signed up a thousand new voters. Most of them, he says, will be for Mr Obama.
Voter registration efforts like this one have gone on across the state.
An estimated 600,000 new voters could participate in this election in North Carolina, the majority of them Democrats. It is easy to see how - in a state where 3.5 million people voted in 2004 - so many new voters can transform the electoral landscape.
"When you're being informed by your peers on a day-to-day basis, it's a whole different ball game," says Damian. "It's the little things which make a big difference."
And once registered, the voter can expect the devoted attention of the Obama campaign.
At the field office in Charlotte, amid empty coffee cups and pizza boxes, we watched volunteers - many of them in their twenties - sift a sophisticated database of likely voters and make call after call late into the evening, cajoling known Obama supporters, arguing with the undecided, asking who needed assistance in getting to the polls.
"Turnout is going to be key in this election," says Paul Cox, the spokesman for the Obama campaign in North Carolina.
"As soon as the polling places open we will have all our volunteers, all our staffers active in getting our voters to the polls."
The state is dotted with what the Obama campaign calls "change crews", 300 of them. These are teams of volunteers under the management of campaign professionals who are meant to conduct targeted canvassing in neighbourhoods they know.
And the Obama campaign has resources. It has reportedly spent about $5.2m on television advertising here, while the McCain campaign has spent about $800,000. It is reported to have more than 300 paid, full-time staffers working in North Carolina. The McCain campaign has 25, we are told.
The Obama organisation is bigger, richer and more aggressive at the local level.
"It's unparalleled," says one Washington politico. "I've never seen a Democratic campaign this organised."
'Taken for granted'
The McCain campaign in North Carolina seemed shocked by the Obama insurgency in their reliably conservative state.
In Gaston County, close to Charlotte, the Young Republicans had organised an evening rally with food, music and games. They had hoped for 500 people but the weather was dicey and only about 70 turned up.
When the Republican Congresswoman Sue Myrick spoke, she sounded downbeat and defensive.
"This year is really going to be a tough one for everybody," she told the attendees. "The Democrats are out-registering us eight to one. They have an active, active organisation."
The crowd looked glum.
Privately, Republican organisers spoke of their frustration and of a lack of direction coming from the McCain campaign.
"We've already lost the youth vote to Obama," said one. "They just have so many resources."
At a McCain campaign office in Cornelius, the Republican Senator Richard Burr stopped by to thank volunteers for their work. Here, the average campaign worker is perhaps 50 or 60 years old.
And the average campaign worker sounded disgruntled. One asked the senator why Mr McCain was "so awkward and halting" in his attacks on Mr Obama. The senator acknowledged that Mr McCain needed to "come out on the offence".
Everyone we spoke to attributed Mr Obama's success thus far in North Carolina to his local organisation.
"Your neighbour, on your doorstep, saying 'I am like you and I am for Obama' or 'I am for McCain': that makes an enormous difference with undecided voters," said Professor Ted Arrington of the University of North Carolina.
"And Obama has people out doing that now. McCain does not, because he took this state for granted."
It is far from certain that Mr Obama will carry North Carolina. His campaign believes that local organisation can turn an election. In three weeks we will know if that calculation was correct. He has already rattled the Republicans. And at the very least, he appears to have turned a reliably Republican state into a battleground.