The Democratic and Republican parties are taking an increasingly active role in Northern Virginia school board races, contests that according to state law are nonpartisan.

In Loudoun County, the Republican Party picked its School Board candidates in the same primary in which it chose nominees for the Board of Supervisors. Democrats in Arlington County held an "endorsement primary" for a School Board seat, making the two candidates promise that the loser would drop out of the November election.

In Fairfax County, Republicans and Democrats already have put together their slates of School Board hopefuls. Candidates who could not get party backing have dropped out, with several saying that they believed they could not win without the campaign help that a Democratic or Republican endorsement brings.

Critics of the parties' growing involvement in school board elections say it isn't what the Virginia General Assembly had in mind when it voted in 1992 to allow Virginia cities and counties to switch from appointed to elected boards. The legislature specified that the elections would be nonpartisan -- no "D" or "R" next to any candidate`s name on the ballot -- on the theory that a panel setting education policy should be insulated from party politics.

Party endorsements in school board races are violating that principle, and making it more likely that voters will see posturing on ideological issues that have little to do with improving schools, said Rosemary Lynch, president of the Fairfax County Council of PTAs. Lynch said that already has happened on the Fairfax School Board, which was elected in 1995 for the first time, as the board's eight Democrats and four Republicans have become embroiled in arguments about such matters as sex education and the federal government's role in education.

"Sometimes you just want to shout, `Enough is enough,' " Lynch said. "Time is wasted on things that aren't important but that people want to debate just so they can get their stand on the record."

The two parties have an even bigger profile in this year's Fairfax election. Republicans announced their endorsements in the spring, months earlier than in the last election. And although 10 candidates ran in 1995 without either party's endorsement, no independents have announced so far this year. Candidates still have until June 8 to file.

Party officials say their endorsements help voters sift through the field of School Board candidates and foster more interest and higher turnouts in the elections.

"They let people know where these candidates stand and give good candidates more leverage," said Emilie F. Miller, chairman of the Fairfax County Democratic Committee and a former state senator. Miller also argues that the party involvement is what voters in Fairfax and other Virginia jurisdictions wanted and expected when they voted in local referendums to switch from appointed to elected school boards.

Whatever the case, it was naive for anyone to think that the political parties would not see school board races as an opportunity to influence school policy and to groom candidates for higher elective offices, said Robert D. Holsworth, director of the Center for Public Policy at Virginia Commonwealth University.

"It is, in some ways, a very predictable thing," Holsworth said. "I'm not sure that when the public overwhelmingly approved elected school boards they knew that they were actually voting for something that would become increasingly politicized. But what we know about politics today is that a majority of the public isn't regularly involved, and that allows those groups that have specific expertise to be very influential."

In Maryland, about half the state's school boards -- including those in Montgomery and Prince George's counties -- are elected. The seats are nonpartisan, and political parties typically do not endorse candidates.

Although 99 of 134 Virginia school boards are now elected, the party activism seems to be most pronounced in Northern Virginia. "I can't even think of any other parts of the state where I've seen party designations of `D' and `R' attached to school board members, let alone committees and endorsements," said David C. Blount, director of government relations for the Virginia School Boards Association.

Although local political parties rarely make direct contributions to school board candidates, they can provide a candidate with access to voter lists, phone banks, volunteers and workshops on how to run a campaign. And being listed in every piece of party campaign literature provides a big boost in name recognition.

In Fairfax, committee members in each party have made endorsements for 11 of the 12 School Board seats.

Nell Hurley, a retired Navy officer and PTA activist, decided to drop out of the race for an at-large seat after she failed to win the GOP endorsement.

"It costs $20,000 to $50,000 to run a school board campaign. And although it's supposed to be nonpartisan, unless you have some sort of major [party] funding and backing, you just can't stand out in the crowd," she said.

Even some of the candidates with party backing say they don't like the system and sought an endorsement only because they thought it would give them more credibility.

"I'm deeply concerned about it -- that's part of my platform," said Jamie Ruppmann, an education consultant who won the GOP endorsement for the School Board seat in the Providence District. "I believe the School Board is much too partisan and much too interested in partisan positions."

But incumbent Fairfax School Board member Gary A. Reese (Sully), who headed this year's GOP candidate recruitment drive, said voters need to be alerted to the important differences in the two parties' philosophies about education.

In general, Republicans on the Fairfax board have favored structured classrooms, increased instruction in phonics, curbs on sex education and a focus on basic subjects. Democrats have tended to favor giving individual schools and teachers freedom to experiment with a variety of curriculum and teaching approaches.

In Loudoun, the GOP is backing candidates for all nine School Board seats. There was competition for the Republican endorsement in three districts, and the winners were picked in the May 22 GOP primary.

"It'll help my candidacy," said Loudoun School Board Chairman Joseph W. Vogric, who beat out two other candidates to win the GOP nod in the Dulles District. "For those folks who aren't going to take the time to look at the individual candidates and at the issues, they'll take the [Republican] Committee's recommendation."

Loudoun's Democratic Party isn't backing School Board candidates, however, and is criticizing the Republicans' approach. "The party bosses should not be making the determination as to who sets the policies of improving our schools," said David L. Whitmer, chairman of the county's Democratic Committee.

Losers in the GOP primary are still free to run for School Board, and Tom Berezoski, Loudoun's Republican Committee chairman, said he fully expects them to do so.

But in Arlington, two candidates vying for the Democratic endorsement for a School Board seat had to promise that they wouldn't run in the fall if they lost the endorsement primary. The party was worried about an unusually strong bid by an independent candidate this year and thought he would benefit if two candidates with Democratic ties were on the fall ballot.

Prince William County party officials so far have taken a more hands-off approach to this year's School Board elections. They said they haven't recruited candidates and don't plan to make an endorsement unless a candidate specifically requests it.

"They've got to ask," said William J. Becker, chairman of the county's Republican Party. "Then again, if one of our good Republicans is running, we don't want to ignore them."

Staff writers Jay Mathews, Christina A. Samuels and Liz Seymour contributed to this report.