The candidate bounced up the steps for the umpteenth time of the day. He rapped on the door, his knuckles white from paint and bruised from four months of this, and waited. This time someone was home, so H. Erle Schafer, Democratic candidate for Anne Arundel County executive, launched into his spiel.

He knew from the white card he held in his hand that the owner of the house was Charles Sands, a registered Democrat with a history of voting in primaries. Since Schafer is locked in a five-way duel for the Democratic nomination, this was the kind of voter he needed to reach.

But Sands, an IBM employe, wasn't that interested. "I was thinkin' of skipping this one," he said politely, folding his arms across his white, button-down shirt. "There doesn't seem to be that much going on. Who else is running?"

Schafer, a state senator, began listing his opponents. There was George F. Bachman, longtime County Council president. There was William H. Brill, a member of the council. There was Elmer E. Dunn Sr., who had run for the office four years ago. "And," Schafer said reaching the end of this list, "there's a boy named Jimmy Lighthizer."

In those last seven words, Schafer put this campaign into a nutshell. There are three major candidates in this race: Bachman, 61; Schafer, 44, and Lighthizer, 36. Bachman says he has the most experience so he should be elected. Schafer, seeing Lighthizer as his major opponent, says he has the necessary experience. And Lighthizer, the youngest, parries by saying that time has passed the older men by.

The reason for this match-up is that Democrats have a good chance of taking the executive's seat for the first time since the position came into being 18 years ago under the new charter form of government. The executive is the county's chief administrative officer, with responsibility for a $329 million county budget and a work force of 2,300, not counting school employes. GOP County Executive Robert A. Pascal must step down now that he has served two terms, and there is no strong Republican candidate.

The best known Democrats and best financed are Schafer and Bachman. But O. James (Jimmy) Lighthizer, a one-term state delegate, has moved up considerably in the polls since the start of the campaign and is now regarded by Schafer, the leader in the polls, as the most serious challenger.

Which brings the question back to the issues of experience, age, time in the county and all of the time-honored rhetorical staples. Schafer was first elected to office 12 years ago as a county councilman. His motto throughout the race, even above his own name on billboards and literature has been: "There is no substitute for experience." Bachman, who has been on the council 18 years, has also spoken on that issue.

Lighthizer is 36 and his retorts from the beginning have been, "Experience without innovation is useless," and, "Their experience is in another era." His billboard motto: "The times demand a new kind of leadership."

Informally, the candidates are more direct with Schafer referring to Lighthizer as, "a boy," while Lighthizer says that Schafer and Bachman are "from the Stone Age."

It is hardly the stuff that turns campaigns into made-for-TV movies. But in a campaign where waste water treatment and zoning that will not affect the county for several years have been the burning issues, in what Schafer has called, "a nonissue campaign," even seemingly minor slights get hackles up.

This is not Prince George's County, where you either are with the "machine," or against it. It is not Montgomery County, where the emphasis on "good government" has driven more than one politician back into private life. This is Anne Arundel, a curious mixture of old-time traditions, young conservatives and Republicans dressed in Democratic clothing. Consider: In a county where registered Democrats outnumber registered Republicans more than 2 to 1, Pascal, the likely Republican nominee for governor this year, won the county executive's race four years ago with more than 65 percent of the vote.

Republicans had hoped that Sen. John A. Cade or Del. Robert Neall, both respected and widely known members of the legislature, would get into the race, but each opted for reelection. Since neither of the Republican candidates, Annapolis Alderman John R. Hammond and former LaPlata Town Manager Raymond G. Boileau, has any name recognition to speak of, this could finally be the year that the Democrats assume leadership.

"They're all saying the right things," Pascal said with a magnanimous smile. "So I'm not getting involved. I've got too many friends in that race to get into the middle of it."

With Pascal staying above the fray, with no particular issue emerging aside from experience versus youth, with candidate forums limited to two or three minutes for each candidate and with money not a major factor, the Sept. 14 primary may be decided simply by who has the momentum when The Day arrives.

Running a campaign in Anne Arundel is an arduous, time-consuming task. The county is spread out over 431 square miles, has grown from 120,000 residents in 1960 to 378,000 in 1980 and, more importantly, is essentially three counties politically.

The north is almost a miniature version of Baltimore, butting up against the city limit. Here, traditional Democratic politicking, including clubs, is the staple. The spawning ground of Schafer and Bachman, this is the most populous area of the county. Since 52 percent of the county's registered Democrats are from the north, if a candidate can dominate this area all he needs to do is run respectably in the rest of the county and he is a winner.

The central part of the county includes Annapolis, which is both the county seat and the state capital. It is suburban-dominated, with a growing number of Washingtonians moving into the area. The southern part of the county is rural, spread out and conservative. There are not many votes to be won here, knocking on doors is virtually impossible, and candidates usually do little more than pay lip service to it. However, some think that in the next eight years, as more people spill over from Prince George's, the south will become increasingly significant.

The three major candidates all come to the race fully aware of their county's political peculiarities. With the lowest tax rate in the state and without overwhelming unemployment, Anne Arundel is a relative oasis of tranquility between Baltimore to the north and Prince George's to the south and west.

"But that's going to change in the next eight years," Lighthizer said. "This county is going to continue to grow, and we're going to have to make a lot of tough decisions about how to control that growth and how to begin dealing with the problems that inevitably come with more and more people."

But convincing voters of this is difficult. The reaction of Sands, the IBM man visited by Schafer, was not unusual. Many people, asked by the candidates what is on their minds, shrug their shoulders. Or they bring up problems that relate to the federal government. So the candidates can only pound away, Schafer and Lighthizer knocking on doors seven days a week, Bachman five, each hoping something he says or does will catch people's attention.

How many will make it to the voting booth on primary day is another of the candidates' concerns. There are 96,000 registered Democrats in the county, but only about 35,000 are expected to vote in the primary, given the apathetic response the candidates seem to be getting as they make their rounds. Because of that, even the tiniest slip-up could be fatal.

"That's why the forums have become a chorus of 'me-too's,' " said Lighthizer, who has tried to pump some life into the campaign with two major position papers. "Nobody wants to get into serious issues because they are afraid they'll make a mistake."

The Super Bowl mentality of politics has taken over: Be conservative and hope that the other guy makes the first mistake.

Those who take the time to study the five Democratic candidates in this election will find them quite different.

Dunn and Brill appear to be the spoiler candidates. Dunn, 52, a fire chief, was the party nominee in 1978 when few Democrats wanted to get into a race where they would be little more than fodder for Pascal in the general election. His fund-raising has been minimal and he isn't expected to finish higher than fourth.

Brill, 49, got into the race late and has raised less than $10,000. He has a doctorate in political science, has taught at Georgetown, and his opponents marvel at his intellect. But they also shake their heads when he fails to appear at forums and they wonder why he is giving up his council seat to run a race into which he seems to be putting minimal effort.

The other three candidates all abandoned safe reelection campaigns to make this race. Bachman, who retired recently after 37 years as a machinist for the B&O Railroad, has been an elected official in the county since the charter form of government was voted in 18 years ago. That fact is the major thrust of his campaign.

"I would not be running if I thought there was another candidate who had the experience to continue what we have started in this county," Bachman said. "But I think Mr. Schafer's campaign motto is the best reason there is to vote for me. There is no substitute for experience. I'm the one who's got it."

Bachman, tall, gray and distinguished, looks more like a college professor than the union man he has been most of his life. His speech, however, is rough-hewn and his accent East Baltimore.

Bachman has raised $93,000, second to Schafer's $125,000 and slightly ahead of Lighthizer's $81,000. Much of Schafer's spending has been on staff and signs

By his count, Schafer has bought 5,000 billboards. Even in a county famous over the years for its Sign Wars, that is an extraordinary number.

But, like Bachman, Schafer thinks name recognition will decide the race. People notice signs. Especially 5,000 of them.

Schafer, the son of a Baltimore meat cutter, says he gave up his seat in the Senate because he thinks the executive's job will be more challenging.

His proudest accomplishment in the legislature was getting the drinking age changed from 18 to 21 this year, after three years of fighting unsuccessfully for the bill.

Schafer is an intense, seemingly tireless campaigner--"relentless," Lighthizer says--who literally runs when door-knocking.

Four years ago, his intensity landed him in the hospital with an ulcer after the campaign. A bottle of Maalox-Plus sits on the dashboard of the van he drives while campaigning.

Schafer's outward drive is quite the opposite of Lighthizer's approach.

A lawyer with a shock of curly red hair and an easy smile, Lighthizer's intensity is equal to Schafer's but not as readily apparent. He is soft-spoken, but was highly regarded in the legislature for his low-key approach.

Which raises the question that both Schafer and Bachman have asked about their fast-closing opponent recently: Why leave the legislature where he is clearly on the rise? Why not run for the Senate?

"My district has a good senator John A. Cade , so I see no reason to challenge someone who is doing an effective job," Lighthizer said. "I think I've got answers for the problems this county will face the next eight years. I've been looking ahead; they're looking back."

For now, none of the candidates can look past Sept. 14. Since the Democratic nominee is likely to be the new executive, the primary is all the Democrats are thinking about.

Their challenge during the next 18 days is to get the rest of the county as concerned about that day as they are.