It's also subprime central. Peppering the streetscapes are the For Sale signs of retreat and surrender to the inevitability of Wilkins Micawber's David Copperfield observation: "Annual income 20 pounds, annual expenditure 19 [pounds] 19 [shillings] and six [pence], result happiness. Annual income 20 pounds, annual expenditure 20 pounds and six, result misery." And on virtually every power pole at big intersections last-resort lenders compete for the business of the desperate.

Avoid Foreclosure! Loans, no credit rating required! And on they go.

For many in Prince William County, however, it's too late. One per cent of houses - more precisely, one in every 103 - are in foreclosure, putting the county among the hardest-hit areas in the nation. The presidential election 17 days away will be won and lost in America's ex-burbs, not its small towns. They are the suburbs where families moved to fulfil the dream of home ownership and now feel the hurt of a recession unfolding across the nation.

Outside Potomac Mills, a huge factory outlet mall in Prince William County, Kim Barclay was heading home after some Columbus Day shopping on Monday. "It's just dipping every day, and people are worried," she said of the economy. "There's a lot of my friends who are living week to week now because of the economy. You drive around my neighbourhood. Last time I counted there was about 50 signs and that was just in two streets. It's like every second or third house is in foreclosure or up for auction."

It has made Barclay think again about the presidential candidates and she is listening very closely to what they are saying about their economic plans. "Right now I think I am still more McCain. I think Obama is trying really hard. I just don't think he has enough experience to run the country. But then McCain, he keeps changing his mind. So what do you do?"

Others, such as Marlane Williams, a middle-aged African American woman, are typical of the new voters helping to change the hue of Virginia voting. She's a committed Democrat and there's no question she's voting for Barack Obama. But for her, the economy is the issue. So far it hasn't hurt her personally, but she has a subprime loan that has not yet reset to the higher interest rate. That occurs in a few months.

Virginia has not voted Democrat since 1964. It is the archetypal example of how America's expanding cities have turned previously Republican states into election battlegrounds.

The polls now show Obama with a significant lead. The CNN/Time poll of 698 voters conducted between Saturday and Tuesday gives Obama a massive 10-point lead, 53 per cent to 43 per cent. Other polls suggest a narrower lead, but there is a pro-Democrat consistency making Obama smile and John McCain sweat. And if McCain loses Virginia, he can kiss the White House goodbye.

Larry Sabato, the director of the Centre for Politics at the University of Virginia, says the national climate is not helping McCain in Virginia or anywhere else. "Most Americans believe the country is on the wrong track, and that is helping Democratic candidates from coast to coast [members of the House of Representatives also go to the polls on November 4]. But in Virginia, specifically, growth in the suburbs of northern Virginia has moderated the political climate and helped to elect two Democratic governors."

The latest US census statistics show Virginia's population grew by 8 per cent between 2000 and 2006 to 7.6 million - about a million more than NSW. Stephen Farnsworth, an associate professor at George Mason University in northern Virginia, says the demographic shift wrought a culture change on the home state of Robert E. Lee. "The biggest growth industry in America is federal government and that includes the military and homeland security. It's led to huge expansion on the fringes of DC and around the southern towns of Virginia Beach, Newport News and Hampton Roads," he said.

The three southern towns are home to some of America's biggest military contractors and the US Atlantic fleet. The new settlers are younger, often college educated, and have young families and mortgages. In many ways, they are the American equivalent of John Howard's battlers.

"The issue in these new communities is the housing crisis," Farnsworth says. "The traditional Christian conservative message is not being as well received as it was because these communities have changed culturally."

Even in communities with strong military ties, the issue of the economy and the impact of falling house prices is taking precedence, although McCain still commands their respect.

At the mall again, a US Air Force officer in his late 30s and with his family explained the competing tensions for military people. The officer, reluctant to name himself because he said he was unauthorised to speak to the media, said he would vote for McCain because: "I respect his experience and I think he's more fit to be a commander-in-chief."

But he says economic concerns are looming large: "If I get orders to go somewhere else, I am going to have to sell my house and move, and I am upside down on my house. It's worth a lot less than I paid for it, maybe $40,000 or $50,000."

The McCain campaign is fighting hard for Virginia, but what works in one part of the state can be a distinct turn-off to voters in other parts. At a rally two weeks ago, McCain's brother, Joe, joked that two Democrat-leaning areas of northern Virginia - Arlington and Alexandria - were "communist country".

The McCain organisation later apologised, but last week as his running mate, Sarah Palin, campaigned in the Virginian capital of Richmond, two men held aloft a placard declaring "Obama = socialist/communist". And the crowd cheered wildly.

Palin is undoubtedly popular in Virginia. Her Richmond rally pulled more than 15,000 to the local speedway. But the crowd was notable for another reason: Richmond's population is 55 per cent black, and 4 per cent Hispanic. The Palin supporters were nigh on 100 per cent white.

Judging by the sea of T-shirts in Republican red, the vast majority at the rally was committed Republican, lured by the new energy Palin has brought to the race.

Dotty Tinsley was one of them. "She's real. She's one of us. She's one of the middle folks and she does a good job in her home state and we would like her to win," says Tinsley from Richmond. "We wish she was No.1 on the ticket this time."

Guliana and Rose Grattan, fiftysomething sisters, are newer converts to the Palin cause. "I was a Hillary Clinton supporter, and I was a Democrat supporter until now. I feel we're being railroaded. I don't like what they did to Hillary and I don't like what they did to McCain-Palin," Rose says.

Guliana was more emphatic. She does not like Obama. "He's not being forthright about his past. He hasn't released his medical records, transcripts, anything to do with the Woods Foundation, or Bill Ayers or his participation in the million-man march with Louis Farrakhan," she said. "He's been less than honest, and that's putting it nicely."

McCain is getting Linda Strange's vote because "he's right for this country". Obama "worries" her, particularly "his going to the church of Reverend Wright for 20 years".

"The man is a man of hatred and that is something that really concerns me. He's now saying they are not his beliefs but you don't change your mind like that. I'm sorry," Wright says.

And that is McCain's problem. In conservative old-school Virginia, Palin is a star; but less so in the struggling ex-burbs of Washington, where the Virginia count may well be decided.

Says Farnsworth: "You win some, you lose some. It's my perception that moderate voters are turned off by Palin, but conservative Christians might turn out in much greater numbers."

Sabato and Farnsworth are still doubtful the Democrats can win a state as traditionally conservative as Virginia. "This state really is a toss-up," Sabato says. "Anyone who says he knows with certainty how Virginians will vote isn't being completely honest. People are still making up their minds."