Fairfax County’s fiercest election battle this year is unfolding in the Braddock District, where the neighborhood concerns and politics are strikingly representative of the county as a whole.

The district, poised midway between the county’s oldest suburbs and its newest subdivisions, has the distinction of being a political bellwether in Fairfax — just as Fairfax has been seen as a leading indicator for Virginia and for suburban voters nationwide.

Today, Braddock also represents American suburbia in its maturity. The district is still home to some of the people who pioneered it, still full of the many charms that lured them there. But the promise of building a life around the single-family home, the automobile, good schools and malls now revolves around addressing the unintended consequences of success: traffic jams, crowded classrooms and fraying infrastructure.

With all seats up for grabs in Tuesday’s general election, many political observers will be watching Braddock’s 26 precincts closest of all next week.

Republicans badly want the GOP’s incumbent, John C. Cook, to hang on to a Board of Supervisors seat that had been in Democrats’ hands for more than 30 years, until Cook’s special-election victory in 2009. Democrats have tapped Janet S. Oleszek, a former Fairfax County School Board member, to get it back.

It is the premier matchup in a year when Chairman Sharon S. Bulova (D) is expected to beat back a challenge from a little-known Republican opponent, and every other board incumbent is unopposed or favored to win.

In a series of debates, the Braddock candidates have clashed over issues that touch on the entire county of more than 1 million people and on minute affairs that affect only neighborhoods. They have differed on the solvency of the county pension system, firefighter staffing, library hours, school spending, affordable housing, transportation and, most of all, the core philosophy a county leader should have.

Cook, 48, styles himself as a moderate Republican who endorses many county services but thinks of the taxpayer first: He has called for reduced government spending rather than property tax increases. But he also plays up his handling of hyper-local concerns.

“That’s just a key part of the job,” Cook said during the candidates’ eighth debate last week. He accuses Oleszek of having a weak grasp of issues and being vague or naive about devising solutions.

Oleszek, 64, portrays herself as a champion of schools, libraries and social programs and has depicted Cook as a part-timer who is too conservative and too eager to oppose spending on important public services.

“It pains me when my opponent votes against the budget that funds this,” Oleszek said during a recent stop at the county’s David R. Pinn Community Center.

Carey C. Campbell, party chairman of Independent Greens of Virginia, is running as an independent; few think he can win. It’s not clear which of the major-party candidates might benefit more from his presence in the race.

Campbell, 55, describes himself as a fiscal conservative. He has pledged to reduce school funding — which absorbs more than half of county revenues — yet advocates building light rail on major thoroughfares such as Braddock Road and installing solar panels on all public buildings. In debates and interviews, he has leveled most of his criticism at Cook.

Portrait of a district

On a radiant fall day for a football game, Robinson Secondary School swarms with families and students in the school colors of blue and gold — and a host of local candidates. Although some Braddock residents at the game expressed satisfaction about their local government, they also talked about the rising cost of living, the tax burden and traffic.

“It’s very well run, but it’s also very expensive,” Rusty Lloyd said. Lloyd, 42, an electrical engineer for the federal government, said taxes seem to be constantly rising.

Marianna Vervena, 49, a stay-at-home parent, had a slightly different perspective: “I feel like we pay a good amount of taxes, and we get a good return on our taxes.”

Both live in a district that evolved as a bedroom community for people who wanted more breathing room near their jobs in the Pentagon or the District. Homes began replacing cow pastures on Ravensworth Farm in the 1950s. With construction of the Capital Beltway in 1960 came an explosion of three-bedroom homes with carports, $23,000 price tags and pink tile bathrooms because, according to local lore, that was former first lady Mamie Eisenhower’s favorite color.

The median market value of a single-family home in Braddock — $476,930 — is not far off from the “typical” household value of $443,551 cited in county budget documents.

Although Braddock tilts slightly Democratic, the district has a reputation as a political barometer. In 2000, Braddock voted for George W. Bush for president. Four years later, Braddock backed Sen. John F. Kerry (D). It also voted for President Obama, but by a smaller margin than the rest of county. In 2009, the district chose Gov. Robert F. McDonnell (R) over Sen. R. Creigh Deeds (D-Bath) and gave McDonnell a margin of victory that was 1.6 percentage points higher than Fairfax gave him.

“You could definitely color it purple,” said Bulova, a Democrat who represented Braddock for more than 20 years before becoming board chairman in 2009.

After this year’s redistricting, Braddock has become perhaps slightly more conservative. It received two new precincts to the west, including GOP-friendly Eagle View, and lost a reliably Democratic precinct, Bristow, in the east.

To the west, the district includes wealthier subdivisions and relatively new, densely clustered townhouses full of young families and singles, not far from a Wegman’s. Thousands of retired federal employees and former military personnel live near George Mason University and Northern Virginia Community College. To the east, the district has attracted immigrants who have created new cultures and communities, such as Koreatown. Those precincts also include more low-income households, including publicly owned dwellings in Heritage Woods.

Bounded by the Little River Turnpike, the Beltway and the Virginia Railway Express, Braddock has thrived because of its handy access to transportation. With the construction of HOT lanes and daily backups on Braddock Road, however, commuters often fume.

“They don’t have any big issues, but they have issues that interrupt their daily lives,” said William Barfield, president of the Braddock District Council of Civic Associations. “Transportation is probably one of the most irritating problems in Fairfax County and in Braddock District in particularly.”

Janyce Hedetniemi , the Fairfax County Democratic Committee’s Braddock District co-chairman, and Larry Krakover, her Republican counterpart, agree on at least one thing: Braddock voters tend to vote based on the candidate, not the candidate’s party.

The matchup

In this year’s race, the candidates’ biggest differences perhaps lie in their approaches to spending priorities.

After approving the fiscal 2010 budget, Cook joined two Republican colleagues on the 10-member board in casting votes against the fiscal 2011 and 2012 budgets because they imposed additional property taxes and levies.

During a tour of the district and in debates, Oleszek has highlighted her interest in schools, criticized Cook for voting against the budgets and suggesting that some school programs were unnecessary. Before her 2003 election to the school board, Oleszek co-founded the Coalition for Good Schools to lift school funding.

As a former School Board member, Oleszek argues that she could build a more collaborative relationship between the Board of Supervisors, which decides how much funding the schools receive, and the School Board, which sets school policies and determines how the money is spent.

Cook said he would support increased school funding next fiscal year so that teachers have raises, but he has also called for cutting administrative costs.