Arlington County Board member Christopher E. Zimmerman (D) easily defeated Republican challenger Mike W. Clancy yesterday, continuing a Democratic lock on the five-member board.

School Board incumbent Mary H. Hynes also retained her seat against challenger Beth Wolffe.

Zimmerman, who garnered almost two-thirds of the vote, said the results were an affirmation of his platform of strong support for Metrorail and livable communities.

"I think voters really responded to the overall concepts of the urban village and the positive campaign we ran," he said. "It's both exhilarating and humbling to receive such support."

Though disappointed with the returns, Clancy said he was successful in challenging the all-Democrat board, particularly on issues related to development.

"I think we were able to get some important issues out there like development and real estate taxes," Clancy said last night. "But obviously you want to win when you run a good campaign."

Zimmerman and Clancy disagreed on several critical issues, including the sales tax referendum measure, which Zimmerman supported; whether the County Board should have reduced real estate taxes further; and the management of the Columbia Pike revitalization.

Zimmerman, 43, an economist, reminded voters that he had sought better mass transit, pushed for targeted development around Metro stations and fought for a greener environment. As chairman of the County Board, one of his key issues has been expanding the county's tree canopy. He consistently pointed to his experience and his knowledge of urban planning as reasons for voters to support his campaign.

By contrast, Clancy, 45, who ran last year against then-Chairman Jay Fisette (D), seized upon the county's escalating property taxes as his main issue. He argued that with the average home assessment up more than 20 percent, the board should have cut the tax rate by 6 cents, not just 3 cents, as it did last spring.

Clancy also accused Zimmerman of being part of what he called a "monopoly" system of government in which too many issues are decided behind closed doors. Zimmerman rebuffed that assertion and pointed to his six years on the board as proof of his dedication to the county.

In the School Board race, the campaign turned largely on how the board should manage its finances. Republican Wolffe, 49, campaigned for abolishment of the annual revenue-sharing payment the school system receives from the county. She said the School Board should instead negotiate annually what it needs. Democrat Hynes, 47, who was seeking her third four-year term, said the board fought long and hard for the revenue-sharing agreement -- which gives the school system 48.6 percent of county revenue -- and should continue the arrangement.

"I think voters really connected with our progressive message," Hynes said. "In a post-September 11 world, people are becoming aware of the need to be more connected with community, and I'm pleased I'll be able to work with them more."

Voters line up at St. Agnes Parish Hall in Arlington. There was one County Board race and one School Board race.