Washington (CNN) -- President Barack Obama arrives in Richmond this weekend for his first official campaign visit to the battleground state of Virginia, a hyped rally that is mobilizing both Republican and Democratic ground troops for the general election.
But the fight for Virginia begins in earnest Wednesday in the Washington suburb of Chantilly, a warren of office parks and shopping malls near Dulles International Airport and just 10 miles from where the first major battle of the Civil War unfolded.
Mitt Romney will campaign at a Chantilly trade show facility and begin his quest to reverse Obama's history-making win in 2008, when he became the first Democrat to carry the state on the presidential level since Lyndon Johnson did so in his landslide 1964 election.
The densely populated suburban swath outside Washington is hardly the only piece of the Virginia political puzzle -- the Richmond metro area and Hampton Roads in the southeast are also critical -- but because of the number of voters and their swingy tendencies, northern Virginia is guaranteed to be showered with attention from the presidential campaigns.
It's a fitting place for Romney to introduce himself to Virginians.
Chantilly straddles two huge counties, Fairfax and Loudoun, that both voted for Obama in 2008.
One out of eight Virginians lives in Fairfax County, and Obama won the county in blowout fashion over Sen. John McCain of Arizona, taking 60% of the vote there.
But the next November, voters in Fairfax, Loudoun and Prince William counties swung back hard to Bob McDonnell, the state's Republican governor.
McDonnell called the Washington suburbs, heavy with small business owners and contractors for government agencies and the military, "tremendously important" for Romney.
"You've got a million people in Fairfax alone," he said. "You've got a couple million in those ring counties. Republicans must do well and at least break even up there to win. You can't get blown out there, as has happened in a couple past elections."
McDonnell, a social conservative who won his race with a relentless focus on jobs and the economy, described northern Virginia as "the biggest collection of independent voters who are fiscal conservative."
"They will vote the issues," he said. "They will vote the person. Mitt has got to spent a fair amount of time there."
Until McDonnell's victory, the region had been trending Democratic in statewide elections for years.
Obama, for instance, won Fairfax County by 109,000 votes. In the 2006 Senate race, Jim Webb won it by 64,000 votes over George Allen. Tim Kaine won it by a similar margin to capture the governor's mansion in 2005.
And John Kerry, despite losing the state to George W. Bush in 2004, won Fairfax by 33,700 votes.
But strategists for both parties say that voters are more fickle than recent election results let on.
"Those voters are far more independent than people give them credit for," said Chris Saxman, a co-chairman of McCain's 2008 campaign in Virginia. "It's the great, classic suburban swing vote. It's where the state legislature has shifted its power. These are key districts. It's a very discerning kind of voter that is closely watching every election."
Democrats admit that in the wake of the 2009 McDonnell wave, the Washington area is no gimme.
"It's critically important in terms of its size and its swingy-ness," said one veteran Democratic operative in the state who declined to be named discussing party strategy. "And anyone who thinks of northern Virginia as a Democratic bastion just doesn't understand the state."
The Obama campaign won in 2008, in large part with organization.
His supporters ventured far outside northern Virginia to find and register new voters in urban centers and traditionally Republican precincts across the state.
That's one reason why Obama is making his "official" re-election debut on Saturday in central Virginia, where Democrats began making gains more than a decade ago when Mark Warner won the governorship in 2001.
The president's rally is at Virginia Commonwealth University in downtown Richmond, offering him the chance to appeal to his urban base while also tapping into the area's suburbs.
At least one senior Republican strategist in the state gave Obama credit for the choice of venue.
"It's a smart location because you're killing a lot of birds," said the strategist, who did not want to be identified while complimenting the Obama campaign. "It's a major city, a large university with a lot of students, and an area where you're going to get a lot of earned media in Chesterfield, Henrico and Hanover Counties, which are pretty significant sizes."
Romney is also taking his campaign downstate on Thursday, when he will rally with McDonnell in Portsmouth, a Navy town in the vote-rich Hampton Roads region along the state's southeastern coast.
McDonnell said Romney needs to hit as many parts of the state as he can between now and November.
"It's very hard for a Republican to win the presidency without Virginia," he said.