They call it "Virginia Man," a 30-second TV ad in which Richmond residents tell why they dislike Democratic gubernatorial candidate Charles S. Robb.

"He wasn't born here," says one man in a down-state drawl. "He just came in."

"He's just running on the coattails of his relatives," says another.

"There are different ways to success," suggests a third. "You can inherit it, you can marry into it or you can work hard for it."

No doubt, this is a nasty ad -- and it is meant to be. Broadcast this week in the southern and western parts of the state by the Republican National Committee, the commercial urges Virginians to vote for Republican candidate J. Marshall Coleman, whose campaign all along has implied that Robb is an outsider who married his way into the political limelight.

It is the latest in an increasingly vitriolic race, and campaign officials say more such ads are likely for a simple reason: They may be the best way to grab the attention of indifferent voters.

"There is no compelling reason for anyone to vote in this election," explains a top Coleman adviser. "There is no compelling issue."

Unlike four years ago, when the two parties offered Virginians a clear choice between a liberal populist and a stalwart conservative, the clash between Robb and Coleman presents two youthful, conservative candidates seemingly well-suited for television politicking, who are trying to capture the same middle-ground voters.

"If you can't separate Tweedledee and Tweedledum on an intellectual basis," says one state GOP media expert, "then maybe you have to hit voters emotionally."

Campaign officials in both camps say the negative turn this campaign has taken was determined from the start. In early polls, Robb and Coleman discovered a few major voter concerns: the state's economy, education and crime. After taking nearly identical stands on those points and bolstering traditional party support, both went after the middle majority and a large group of undecided voters faced with strikingly similar candidates.

"There are a whole lot of hot buttons waiting to be pushed," says John Stevens, director of the Republican Governor's Association. "We're still trying to find out what those buttons are." So with Robb and Coleman practically indistinguishable to the voter, the only thing left was to get Virginians excited about voting against the other man.

"I don't know after 25 years in this business what motivates people to vote," says political consultant Joseph Napolitan. "What I do know is that maybe it's easier to get people to vote against something than it is to get them to vote for something."

Both candidates hired media consultants well-schooled in the art of the negative -- Robert Squier, for Robb, and Douglas Bailey, for Coleman. "There's nobody who has sharper elbows than Bob Squier," says pollster Pat Caddell.

But the art of negative campaigning holds potential danger if voters believe you have crossed the thin line separating fair play and impropriety. Countering a Robb commercial asserting that Coleman was lax in prosecuting drug crimes, Bailey wrote a radio spot defending Coleman's record and offhandedly joked that Robb must have been smoking marijuana. Loudly cheered by Coleman staffers, it created a furor around the state and finally was pulled off the air when Coleman's pollster, Richard Wirthlin, reportedly told Bailey: "The only thing I remembered about it is that Robb smokes marijuana."

Squier has drawn on Coleman's performance as attorney general to produce negative ads portraying the Republican as waffling on issues over the years. These attacks, which Coleman aides charge prompted the negative media exchange, frustrated the GOP camp because Robb had little public record to criticize.

Recently, Repubican officials in Washington dispatched one of their top strategists, Kenneth Kling, to Richmond to bolster the Coleman campaign. Kling is described by associates as a blood-and-guts fighter who is now masterminding the negative media blitz against Robb. In the two remaining weeks of the campaign, they say he is planning to pepper television, radio and newspapers around the state with attacks on Robb's background and character.

Some regard such tactics as part of political gamesmanship. But the immeasurable worry is how many potential voters does all of this turn off? The final campaign media barrage is designed to reach 90 percent of Virginia's television viewers. In the last five weeks of the race, the average viewer will see a Coleman or Robb commercial between 12 and 15 times.

At the same time that television has brought candidates easy access to the home, its long-term effects on how people view politics are largely unknown. "The decline in voter turnout is proportionate to the increase in the number of television sets in people's homes," says Napolitan.