In 1979, Democrat Mary Margaret Whipple, a longtime Arlington civic activist and School Board member, narrowly lost a bid for one of two seats on the County Board.

Last November she ran again for the board, this time with the backing of the largest schoolteacher organization in the county. She won, ousting County Board Chairman Stephen H. Detwiler with a lopsided victory that restored the Democratic Party to control of the county government.

To many Arlington politicians, the Arlington Education Association and its political action committee were the difference. Teachers, says Detwiler's campaign manager Robert E. Harrington, are a major reason the Democrats won last year.

This fall the teachers will be lining up again, seeking to help the Democrats capture two more seats on the five-member County Board. In the process, they are taking aim at Republican Walter L. Frankland Jr., who has been an outspoken critic of the teachers' politicking and has accused the board Democrats of making "political payoffs" to keep the teachers in their camp.

"Putting it bluntly," says Cathy Hartness, head of the teachers' political action committee, "we'd like to see him replaced on the board, and we want our endorsed candidates to win."

"That's nothing new," says Frankland. "They didn't want me there in the first place, and they didn't want me reelected. I believe all the organized Democrats are certainly out to defeat me . . . despite all the things I have accomplished for education and the taxpayers."

The teachers see Frankland's eight years in office differently. "All I can think of is all the years he's been on the County Board and the things he hasn't done for the schools or has tried to put obstacles in front of," says Paul Moran, the association president. "And now he's trying to portray himself as a friend of the schools. It's frustrating."

That frustration will drive a cadre of volunteer teachers to work for Democratic board candidates Albert C. Eisenberg and Richard A. Buffum and Arlington's Democratic state legislators this fall. As they did for Whipple and other Democrats last year, an estimated 100 teachers will staff telephone banks, recruit other volunteers, canvass neighborhoods with literature, volunteer to be poll-watchers and drive voters to the polls.

The candidates will have other volunteers, but teachers represent the largest single source of local campaign workers in Arlington. Many voters in the county are federal workers and thus barred by the Hatch Act from participating in partisan politics.

Teacher groups in Alexandria and Fairfax say their organizations are politically active, but not as successful as the Arlington teachers. "I think all teachers are waking up to the fact that every decision about education is a political decision and everyone has a vested interest in it," Hartness said.

Because Virginia school boards are appointed by county boards and city councils, teachers across the state have begun concentrating more heavily on local elections in recent years, as well as on state legislative races.

"I think the change in the composition of the Arlington School Board brought home to them the impact of local elections," says Whipple, referring to the Republican-dominated School Board.

A number of Arlington teachers have spent recent summers attending a "political action school" sponsored by the Virginia Education Association. There, they say, they are taught how to organize and run a political action committee, set up telephone banks, raise funds, recruit volunteers and lobby public officials.

The lessons have been brought home. Bonnie Pfoutz, one of the Arlington PAC officials, says 437 teachers of the association's 780 members belong to the PAC and between 80 to 100 of them get actively involved in campaigns annually--enough to give their candidates about two extra precinct workers at each of the county's 39 precincts. That's more workers than some Republicans say their entire precinct operations fielded last fall.

"I don't think the teachers' endorsement is so important as the number of bodies they have manning the polls and distributing literature," says Frankland, who has called the teachers "a potent political force," though the PAC does not contribute to county campaigns.

He and other Republicans have complained about teachers who don't live in Arlington campaigning in the county and that the teachers seem to invariably back Democrats, who have supported collective bargaining for public employes, a practice the courts have outlawed in the state.

The Arlington teachers, who had collective bargaining in the county until that court ruling in the late 1970s, respond that Democrats have historically been more supportive of their needs and say their endorsements are based on voting records as well as the candidates' stands on collective bargaining and other issues.

They point to the decision by the Democrats on the County Board last spring to appropriate an extra $250,000 to attract and retain quality teachers, a move the board's two Republicans at first fought and that Frankland branded a "political payoff."

Frankland has infuriated the teachers by urging that they be placed under the county's "little Hatch Act," which bars county employes from participating in county elections.

School Board Chairman Simone J. Pace said his board is awaiting legal advice on Frankland's proposal and won't predict what the board will do.

Pfoutz predicts that any such move would be overturned in court. "The historical reason for such legislation," she said, "was to protect employes from political coercion, not prevent them from participating."

Frankland says that he was advocating stronger classroom discipline, more rigorous curricula and an end to educational experiments such as unorthodox courses and open classrooms years before the National Commission on Excellence in Education came out with its report critical of public schools last spring.

"As a representative of the taxpayer," he says, he also has had "to take into consideration the total money available and strike a balance between the limited amount available and what services were needed."

A major reason Frankland and his running mate, Michael E. Brunner, a former school board member, failed to get the teachers' endorsement was their opposition to collective bargaining. Brunner is running for the seat currently held by Republican Dorothy S. Grotos, who is running for county treasurer.