It is probably as close as I will ever come to having an intimate shared experience with Barack Obama.

Yesterday morning I sat in his customary black swing chair at his local barber's shop while Zariff, Mr Obama's hairdresser, cut my hair with the very same scissors and comb that he uses on the future First Follicles.

No matter that I have thinning, lank, Caucasian hair - not tight Afro-American curls like the man who will almost certainly be elected America's 44th president today. Zariff was still able to give me the 'Obama cut' - medium length, tapered back and sides, no hard lines - that he created for Mr Obama before his speech to the 2004 Democratic convention and is now asked for a dozen times a day.

As Zariff snipped, we talked. Mr Obama was in the shop last Monday, he said, and he expected him to return before he delivers his anticipated victory speech to a million adoring supporters in Chicago's Grant Park tonight. "We have to make sure he's looking good when he goes out there," said Zariff, 45, who uses just one name.

The burly former martial arts instructor has been cutting Mr Obama's hair for 14 years. He is "Smitty" - the pseudonymous character in Mr Obama's autobiography 'Dreams from my Father' who told him how Harold Washington, Chicago's first black mayor, inspired the city's huge African-American population. He said Mr Obama used simply to stroll down from his home in Chicago's Hyde Park district to the modest shop on South Blackstone Avenue with its blue and red striped barber's pole, but not any more.

Today he arrives in a motorcade, and 20 or more secret service agents take over the premises inside and out. "They may even be in the ceiling," Zariff joked.

Customers already in the shop are allowed to stay, but no new ones can enter. Mr Obama "gets my undivided attention," said Zariff. "I have to get him out in 20 minutes. More than that and people get on their cell phones and a huge crowd gathers outside." Only one customer has ever objected to him jumping the queue. "She had to be a Republican," Zariff quipped.

Zariff is probably the only man in the world who can wave razor-sharp blades within an inch of Mr Obama's throat. "The secret service had to get used to that. He trusts me 100 per cent, of course, but their job is to trust noone," he said.

Zariff snorted at the rumour that Mr Obama dyed his hair black, but is now letting it turn grey to give him more gravitas. "He absolutely uses no dye at all," he insisted. Asked about Mr Obama's sticky-out ears, he replied curtly: "If God gave you big ears you have to work with it." He has "magic hands", he said of himself.

Mr Obama and the other customers discuss sports, goings-on in Hyde Park and what is happening in Chicago - "a guy who travels so much has to keep up with what's going on at home," said Zariff. "He doesn't act like a celebrity...He's very nice, very engaging, humble. He's the first to tell you 'treat me like everyone else'." But they only discuss politics if Mr Obama brings it up "and then we jump on it".

Haircut over, Mr Obama pays $21 - the same as everyone. It is a far cry from the $200 President Clinton paid the Hollywood stylist Christophe in 1993 while he sat on the tarmac of Los Angeles airport in Air Force One with two of the four runways shut down. Or the $400 John Edwards paid for a haircut by another celebrity stylist during the Democratic primaries.

Tonight the Hyde Park Hair Salon will be cleared of all its furniture except Mr Obama's (and my) chair, and more than a hundred guests will pile in for what they hope will be a joyful celebration. "I'm very excited. This is a huge event and very momentous...It's a true testament that anything can happen in America," says Zariff.

A few miles further north one of the biggest crowds ever to gather in Chicago will fill Grant Park - an expanse of open ground on the shore of Lake Michigan best known as the scene of violent clashes between the police and anti-war demonstrators during the 1968 Democratic convention.

The city's entire police force will be on duty. Downtown businesses will close early. The surrounding roads will all be sealed off. The weather - and political - forecasts both look good, but the authorities scarcely dare to contemplate what would happen if, after such a build-up, Mr Obama somehow lost.

Zariff is not contemplating defeat either. He already anticipates cutting Mr Obama's hair for his inauguration, and expects to make regular trips to Washington when Mr Obama is in the White House. "I'm very, very sure I will," he says. "If he's signed up for eight years I'm signed up for eight years. That's my duty...I feel very proud. I'll be the first African-American barber to serve a president."