海角大神

At the end of a leafy cul-de-sac in Virginia鈥檚 Prince William County, Chris Casey鈥檚 house isn鈥檛 hard to find: It鈥檚 the one with the big Obama banner draped across the front porch.

Inside, his living room looks like a campaign office. Stacks of literature are divided into two piles 鈥� 鈥淧ersuasion,鈥� for the regular voters who are leaning toward Democratic nominee Barack Obama, and 鈥淪poradic,鈥� for the sometime voters who need a nudge just to turn out.

Mr. Casey has lived here for 18 years, but suddenly, without moving, he鈥檚 in a swing state. For the first time since 1964, Virginia is threatening to vote Democratic for president. If it does, that could hand the election to Mr. Obama. So Casey has joined the legions of Democrats out nights and weekends, knocking on doors, chatting with voters, and handing out literature.

When he finds a willing listener, his message is blunt: 鈥淚f Prince William County goes blue, then Virginia goes blue, and if Virginia goes blue, then we get the White House.鈥�

That may be oversimplified, but the importance of Prince William County 鈥� a fast-growing exurb of Washington, D.C. 鈥� cannot be overstated. Prince William, along with neighboring Loudoun County, has seen explosive population growth so far this decade: in Prince William, a 37 percent increase as of 2007, and in Loudoun, a 58 percent increase as of 2006.

Many of the new residents are from other parts of the country and the world, not locked into the traditions of Virginia.

Both are now among the highest-income counties in the country, cutting into the predominance of working-class Republican voters.

In addition, the housing downturn and high gas prices have hit the outer suburbs especially hard, making this fertile turf for Obama. In Prince William, the median price for a single-family detached home has dropped 41 percent in the last year, as foreclosed properties have flooded the market.

George W. Bush won Prince William County in both 2000 and 2004, but now Obama has the edge. An Oct. 14 survey by Politico/Insider Advantage shows Obama leading Republican nominee John McCain there 50 percent to 42 percent. In the age 30-44 group, Obama is ahead 58 percent to 33 percent, and among independents he leads 55 percent to 25 percent.

But there are plenty of other parts of the state where Senator McCain can make up that deficit, and observers in Virginia say the state will be close.

鈥淒on鈥檛 be fooled by that CNN poll,鈥� which showed Obama up in Virginia by 10 points, says Larry Sabato, a political scientist at the University of Virginia at Charlottesville, who faults the methodology of that and other polls that show Obama with a sizable lead here. 鈥淚f Obama wins Virginia, it will be by a point or two or three. It鈥檚 very competitive.鈥�

Mr. Bush won Virginia by eight points in both 2000 and 2004, and there鈥檚 no way the state will swing Democratic by a similar margin at the presidential level in just four years, he says. But Virginia has been trending 鈥減urple鈥� for a long time. Democrats have been winning statewide all decade, including two governor鈥檚 races and the Senate race in 2006 that saw Democrat Jim Webb narrowly beat the incumbent, George Allen, after Mr. Allen was caught on video uttering a racially tinged word: macaca.

Former Gov. Mark Warner (D) is expected to easily replace retiring Republican Sen. John Warner (no relation) on Nov. 4. But what gives Obama a chance here is the economy and general unpopularity of the Republican Party. 鈥淚f this weren鈥檛 a good Democratic year, Virginia wouldn鈥檛 be a tossup,鈥� says Mr. Sabato.

Obama has also benefited from the competitive Democratic primary here last February, which forced him to set up campaign operations all over the state and identify local talent and volunteers. The Democrats鈥� 鈥淐ampaign for Change鈥� has 49 offices around the state, versus 21 McCain/GOP 鈥渧ictory centers.鈥�

But the McCain campaign is talking confidently. 鈥淲e have a very aggressive voter-outreach program,鈥� says McCain spokeswoman Gail Gitcho. 鈥淲e have always maintained that Virginia would be a battleground state, and we have taken nothing for granted.鈥�

And even if Northern Virginia 鈥� accounting for one-third of the state鈥檚 population 鈥� goes heavily for Obama, McCain can make up the deficit in other parts of the state.

鈥淭here are three metro areas in Virginia, and whoever wins the state has to win two of those,鈥� says Quentin Kidd, a political scientist at Christopher Newport University in Newport News, Va.

Obama will clearly take northern Virginia, and McCain will clearly take the area around the capital, Richmond, he says.

鈥淭he real battleground is Hampton Roads,鈥� Mr. Kidd says, referring to the coastal region of southeast Virginia, which has a large African-American and military population. The area also has many younger voters, including college and university students who could help Obama.

Back in Prince William County, Chris Casey is working off a list of prescreened potential Obama voters. To those who say they鈥檙e definitely voting for Obama, he suggests voting early, given the predictions of long lines on Election Day. But some on his list remain undecided.

Koeen Madsen, an assistant principal at an elementary school, says she鈥檒l probably vote for Obama, but McCain鈥檚 running mate has given her pause. 鈥�Sarah Palin is a breath of fresh air,鈥� says Ms. Madsen. 鈥淪he鈥檚 inexperienced, but she seems real. She talks like the rest of us.鈥�

But for another voter in this suburban enclave of townhouses, Governor Palin is a net negative. 鈥淚 don鈥檛 like Obama, because his running mate has more experience than he does,鈥� says Brandon Hall, who works for Media General. 鈥淲ith McCain, it鈥檚 the running mate that鈥檚 the problem.鈥�