Virginia's 8th Congressional District - where an incumbent Democrat is colliding with a Republican holding local office in a battle to attract a majority of middle-income independents - is, from a national view, a classic race for Congress.

But from a local perspective, the race between Rep. Herbert E. Harris II and John F. Herrity fractures into the sort of shifting, multi-faceted mass of uncertainties that local races usually are.

Major part of the problem is the distriot itself - southern Fairfax County, Alexandria, Prince William County and northern Stafford County.

Its roughly 220,000 registered voters in a population of more than a half million are extremely transient. By some estimates, one-third of the voters in 1976 will have moved away by Nov. 7, 1978.

And as part of metropolitan Washington, its residents share newspapers and television stations with the District and Maryland suburbans with the District and Maryland suburbs and may be as familiar with Jody Powell or Tip O'Neill as with their own congressman.

Further, Virginia's absence of party registration makes indentification, of friend or foe, difficult.

The combination causes both Herrity, chairman of the Fairfax County Board of Supervisors, and Harris, seeking a third term in Congress, to agree that the most important element in the campaign is the strength of their volunteer, grass roots organizations and their ability to find and get out the vote.

There are other similarities between the two: Both are graduates of the Georgetown University Law School and developed politcally in Fairfax County. Each man has five children. And both are aggressive and outspoken (abrasive in some views).

Harris, 52, and Herrity, 46, agree that inflation is the number-one problem on the public mind, and both see that issue as the key to capturing the decisive independent vote.

Herrity is attacking Harris as "the biggest spending congressman in Virginia" and citing his own record in Fairfax an attempting to limit the cost and [WORD ILLEGIBLE] of government.

Harris Points to Herrity's frequent votes on the losing side of Fairfax issues and says Herrity "has been an ineffectual public official" Harris also has keyed his reports from Congress, which are mailed to 180,000 residences in the 8th District, to cutting local taxes and fighting inflation.

On an array of other issues of vital interest to the district, the two men are in basic agreement.

Both oppose the Civil Service reform bill, a dangerous issue in a district full of federal workers, and back impact aid to schools Both are against allowing Washington to tax commuters and favor more federal funds for Metro.

Herrity's campaign manager is Don Allen, who has just completed four years on the staff of the Republican National Committee. The headquarters is a neat storefront building in a Springfield shopping center.

Allen estimates the campaign will cost $150,000 to $200,000 (Harris expects the GOP to spend $250,000 in the campaign) and plans to use perhaps 60,000 pieces of targeted direct mail and heavy door-to-door campaigning by the candidate and volunteers.

Allen says he now has a card file of 2,200 volunteers and would like to line up 5,000. He says Herrity will campaign door-to-door four days a week for three hours a day.

Herrity, who says he expects a turnout of about 55 percent in this off-year election, described his political base as "Springfield, but the strategy is to do well over all.

"I run my own campaign," Herrity says. "Everything that comes out of this office is scrutinized by me personally."

Herrity says he has already hit about a thousand homes going door to door, a technique he enjoys and which he says helps find volunteers and keeps a candidate in touch with the community. He says he is considering use of television but that direct mail retains top priority.

Herrity, who suffered two heart attacks in 1976, confronts his health head on, running 3 1/2 miles a day and citing a doctor's statement that he is in better condition than 90 percent of men his age.

Harris' headquarters is in the basement of a Springfield office building surrounded by warehouses. His campaign manager, Linda Golodner, has worked in Harris campaign since 1972, and the office looks like it may not have been straightened up in that span.

Golodner says the 1976 campaign cost $80,000, and this one will run about $150,000. She hopes to have 2,000 volunteers in the campaign and is concentrating on precinct canvassing Media and direct mail use will depend on the amount of funds raised, she says.

Harris, who prides himself on a 99 percent voting record in Congress and has decided he cannot simultaneously campaign heavily and keep up with legislation in the closing weeks of the session, says, "Once we adjourn, I'll campaign seven days a week, morning to night. I'm a door-to-door guy and have been."

Harris says that television is too expensive and only one-fifth of its audience would live in the district. "The element we will rely on the most is the door-to-door flier," he says. "And we know how to do phone banks."

"The key from our standpoint is to get our message out. I am proud of our record. We work hard at serving this district," Harris says, stressing constiutent service and legislation important to the district.

Harri says that Herrity has better name identification than his test opponent but that Herrity also has a stronger negative reaction factor.

Right-wing organizations will pur money into his opponent's campaign, making it impossible to match the Republicans dollar for dollar, he says.

The Republicans counter that the value of being the incumbent is worth a great deal, including free mailing for a quarterly newsletter.

"I'm the distinct underdog in this race. I don't have any illusions about that," Herrity says. "Whether we win is up, to a great degree, to the ability of our volunteers to identify our support and get it to the polls."