By the standards of low-level, mudslinging and downright dirty political campaigns, the Democratic State Senate primary in Montgomery County's affluent and well-educated 15th District has it all: a powerful incumbent whose wife made anonymous telephone calls to the challenger, the challenger who called a press conference to play cassette tapes of the calls, a local newspaper editor who trailed a Mercedes Benz as the driver ripped down campaign posters, and a charge of conflict of interest over how to dispose of rotting crab shells.

And then there's the challenger's latest accusation. He says he narrowly avoided being seduced by a beautiful woman wearing skimpy designer running shorts and a tight T-shirt. And then an anonymous caller told his pregnant wife about their imaginary affair, he says.

"It's crazy, it's absolutely crazy," says the powerful senator, Laurence Levitan. "I can't take much more of it. How can I continue?"

Says his challenger, Anthony Puca: "This isn't a campaign, this is a war. We're using guerrilla warfare and hitting them from every side."

And so it goes in what has become the liveliest political race in Montgomery County, the only local race so far in the Washington area to warrant a story in the Wall Street Journal.

Of course the tone of this campaign may not be so unusual, given that the 15th District is also the home of gadfly Republican Del. Robin Ficker, the candidate who once dressed up as Santa Claus to hand out literature in a shopping center, and who in 1972 accepted money to launch a Ted Kennedy write-in campaign, only to find out that his anonymous donors worked for the Nixon White House.

But even by the standards of the 15th, this year's State Senate race is nothing short of bizarre.

"It certainly is out of the Montgomery County genteel tradition," says Del. Gerard F. Devlin (D-Prince George's), a casual observer of the combat. "In the richest, most educated and affluent county, normally noted for its pitty-pat fights and Harvard-Yale debates, they've got a real Hoboken waterfront brawl."

The setting for the match is indeed unusual, since the 15th District includes wealthy Potomac, home of vast polo grounds, fox hunts and exclusive country clubs for the county's landed gentry, where homes average $200,000 and sit hidden on lots of least two acres.

The brawlers themselves are an unlikely pair for such a gut-level fistfight. Levitan, a Washington and Lee University graduate with a law degree from George Washington University, was the Maryland Chamber of Commerce's 1981 "Citizen of the Year." Puca, a 1969 University of Maryland graduate, was one the National Jaycees' "Outstanding Young Men of America" in 1979.

Levitan, seeking his third term, is chairman of the powerful Budget and Taxation Committee, a post he says allows him to bring additional revenue and tax relief to Montgomery County. But his critics charge that the chairmanship -- and some big business clients of Levitan's well-connected law firm -- have made the senator more concerned with special interests than average citizens. Levitan denies those accusations.

"No question about it, I've been probusiness," Levitan says. "But as chairman of the committee, I'm in a key position to help the county." Levitan says he has written some "proconsumer" initiatives, including new tax breaks for homeowners.

The challenger, Puca, is a businessman and president of American Business Services, an office equipment firm. He is no stranger to county politics, having run unsuccessfully for delegate from the district in 1978. He says he decided to run for Senate this time because, "This is it. It's like Aquarius. The moon, the stars, everything is in the right place."

Puca calls his race this year against Levitan "the most important political race in the state." He derives that lofty analysis from the fact that Levitan is chairman the committee that earlier this year killed a corporate tax bill, thereby giving corporations some hefty new state tax breaks.

Puca compiled into a newsletter eight pages of newspaper articles about Levitan's record on ethics legislation, a proposed tax on country clubs, and his alleged conflicts of interest. The newsletter is being mailed to 15,000 registered Democrats. "I'm trying a new campaign tactic," Puca says. "It's called the truth."

Puca, meanwhile, fell into his own conflict-of-interest trap over the thorny question of what to do with the state's mounting pile of smelly, rotting crab shells. An estimated 20 million pounds of picked-over shells are piling up each year in landfills -- an obvious state crisis. Of course, not a single rotting crab shell has ever been spotted in Montgomery County, but the state crisis prompted Puca to propose a solution.

In a "Dear Harry" mailgram sent to Gov. Harry R. Hughes, Puca suggested a new technique for turning the crab shells into fertilizer. Puca later said a friend of his has patented the technique, drawing charges of conflict from Levitan. Puca retorted that Levitan is "Mr. Conflict of Interest" with his probusiness record. Levitan called Puca "a liar."

The two carried their back-and-forth sniping into a short article in a recent Wall Street Journal. Says Levitan: "Get this. He accused me of being probusiness in the Wall Street Journal."

Levitan's wife Barbara, meanwhile, was so upset about the newsletter that she called Puca's home three times and left messages on his answering machine. "He got my wife so upset she called him and told him what she thought of the piece," Levitan says.

Puca, meanwhile, called a press conference and played the tape for a roomful of reporters. In one, the voice said: "You are an out-and-out liar." Puca, who called the taped messages threatening and harassing, announced that he was asking the state's attorney to investigate and tap his telephones.

Levitan points out that the Puca newsletter asked for comments from readers. "He asked for comments and I guess that's fair comment."

Puca had another complaint, which he lodged with Democratic Party Chairman Stanton J. Gildenhorn. He said Levitan supporters were ripping down his campaign posters and removing his literature from car windows, and he demanded an investigation by the party's ethics committee. Then on Sunday, Marty Moore, editor and publisher of the biweekly County Express, said he spotted the driver of a green Mercedes selectively ripping down Puca posters in Gaithersburg.

Moore said he called Levitan to find out the identity of the mysterious Puca poster-ripper, but the senator angrily hung up on him. Levitan replies, "I don't authorize it, I don't condone it. But it happens every once in a while." As for hanging up on the editor, Levitan says, "I did. He interrupted my dinner. I said I didn't need to listen to this, so I hung up."

And last week at the supermarket, the proposition came. Puca says he was approached outside a Safeway by a woman he believes to be working on Levitan's behalf, who tried to lure him into a preprimary tryst. He described the woman as scantily dressed, in a tight T-shirt and short, short designer running pants. "She said, 'I'll do anything for you! Why don't you come over?' " Puca says.

Puca says he didn't take up the offer, but that the next day his wife Lorraine got an anonymous call from a woman who said Puca was sleeping with her and about three other women.

Levitan says he doesn't know anything about the Puca proposition. But, Levitan adds, "He must have been a man of steel if he turned down an opportunity like that. I'd like to find out who she was."