Democrats in Northern Virginia are increasingly focusing their General Assembly campaigns on guns in schools, an issue they predict will bring suburban parents to the polls to help them defeat a group of Republican incumbents.

They're hammering these GOP legislators for supporting a measure that would have allowed students to keep rifles and other guns locked in their car trunks on school grounds so they could go hunting after class.

Many Democrats began their campaigns this summer by challenging Republicans on the state's traffic congestion, a potent issue in Northern Virginia suburbs. After the school year began, Democrats said, they started to shift their focus toward school safety.

After studying polling data identifying guns on school property as a potentially decisive issue, challengers are relentlessly pursuing it in mailers, phone calls, political forums and door-to-door campaigning. It has become an issue in the majority of House races in Northern Virginia where there are Republican incumbents, and in some Senate races as well.

The Democrats invoke images of Columbine and other school massacres, saying easy access to guns could lead to similar incidents. Two Democratic candidates called news conferences featuring the mother of a student killed last year in an Arkansas school shooting. Democrats are planning a rally today in Falls Church to again call attention to Republicans' records on gun issues.

"This is truly on the minds of voters, especially women," said Shawn Matteson, campaign manager for Kelly Burk, a Democrat who is running against Del. Richard H. Black (R-Loudoun). "You've got these soccer moms here, and they're worried. . . . [They] aren't going to tolerate the fact that Dick Black has voted to allow guns on school property."

Republican incumbents say their challengers are campaigning on a non-issue and misinterpreting the legislative vote. But at a time when gun-control measures have gained ground in Congress, Democrats in the suburbs think the issue will give them the edge they need in November's voting.

Republicans, already in control of the state Senate and virtually tied with Democrats in the House, hope to grab control of the General Assembly for the first time since Reconstruction.

Black and other Republicans who supported the gun measure said that Democrats are distorting the proposal's impact and that it was designed to help rural parts of the state where students often go hunting after class. Black said that it would not have led to Columbine-style violence and that Republicans have come forward with more effective crime-fighting measures.

"The children who carry out those crimes are willing to violate the criminal prohibition on premeditated murder," Black said. "Telling them in addition that they might be expelled from school . . . is probably not going to have a very big impact." Black said Democrats had picked a "rather silly issue, because everyone is in agreement that we should have guns off of school grounds."

Democrat James E. Mitchell III, running a campaign focused on the gun issue in Fairfax County, sent out a campaign brochure that features an image of a deer in the cross hairs, along with a school building. Under the deer, the brochure reads: "Delegate Roger McClure believes hunting is so important that children should be allowed to bring their guns to school--so they won't waste a minute before heading out to go hunting after school."

Mitchell said his opponent's record shows he's "completely out of touch with reality," and he said he plans to press the issue in every debate. McClure (R-Fairfax) said that Mitchell was blowing a minor vote out of proportion. "They have to divert everybody's attention from our great transportation program, our education program," McClure said.

In some races, Democrats are criticizing their opponents for votes on other gun measures, such as allowing guns in recreation centers and concealed weapons in restaurants. But most are talking about guns in schools.

Until the last session of the General Assembly, state law called for the expulsion of students who took guns to school but exempted students who kept guns locked in their car trunks for hunting. A lawmaker proposed a measure that forbade students from bringing guns altogether.

Lawmakers ultimately agreed on a compromise: Bar the guns from school grounds but allow school boards to overturn the prohibition for students who want to lock weapons for hunting in their trunks. Then Gov. James S. Gilmore III (R), a fervent gun rights supporter, proposed an amendment that his office said would have allowed guns to be kept locked in trunks unless school boards banned them. However, gun-control advocates said Gilmore's amendment would have prevented school boards from banning guns for hunting.

Legislators voted twice on Gilmore's amendment, which ultimately failed. Several said they changed their votes the second time because they originally did not understand the amendment.

Now some of those vote switchers--including Dels. Michele B. McQuigg (R-Prince William) and James H. Dillard II (R-Fairfax)--are coming under fire. Their opponents say they cannot be trusted if they could mistakenly vote for such a measure.

"How do we know she's not going to be confused again?" said McQuigg's Democratic challenger, Virginia M. Stephens, who has highlighted McQuigg's votes on a mailer headed "Important Back to School Information."

Eileen Filler-Corn said she decided to get into the race because she was outraged by Dillard's first vote. She sent voters a letter saying that just about everyone she talks to "has been as horrified as I am that our delegate would vote to allow guns on school properties."

McQuigg said that she was confused about her first vote and that by attacking it, her challenger is showing that she "doesn't understand the legislative process." And Dillard, who said he was misled to believe that Gilmore's measure strengthened existing regulations, said he switched his vote after learning otherwise.

Lila Young, a spokeswoman for Gilmore, said the gun issue is a moot point because the governor's amendment failed. Gilmore signed the compromise legislation into law--without his amendment.

"It's not going to come back up," Young said. "It's simply being used to frighten people in Northern Virginia because transportation didn't work."

The Democrats' focus on guns in schools poses a little problem for their state party chairman, Del. Kenneth R. Plum (Fairfax). Early in the legislative process, he cast a vote--inadvertently, he later said--to water down the gun-control legislation. Soon after, he inserted wording in the legislative record saying he had made a mistake.

Now Plum's Republican challenger, Michael N. Pocalyko, is criticizing Plum's vote.

CAPTION: Del. Richard H. Black (R-Loudoun) calls the vote under fire by Democrats a "rather silly issue."