On Mother's Day one year, Neal Potter took his wife, Marion, on a short trip: They visited a sewage treatment plant.

"Well, she enjoyed the ride out in the country," Potter said later about the holiday mission to find out if the plant created an odor in the surrounding neighborhood. (It did not, he said.)

That is a vintage Neal Potter story. There is also the one about him donning hip boots and standing in a stream near Poolesville to see if the bridge above really did need a million-dollar repair. And the one about Potter, at 75, loping up five flights of stairs at the Montgomery County Council office building several times a day. ("Two at a time," he always says.) And the one about the stack of zoning maps falling on a job applicant's head as she sat in his office.

"He just brushed them aside and kept talking," said Kelly Pelz, who went on to become his aide seven years ago.

As Potter, who has served a record 20 years on the council, continues his surprise bid to unseat County Executive Sidney Kramer, a successful businessman, the personalities of the two Democrats seem to define the closer-than-expected race. Here is Kramer, a take-charge type, versus Potter, someone who likes to take another look -- and another and another.

Potter's attention to detail, his economist's love of analysis, his reputation for honesty, his knowledge, his workaholic ways, are the very traits that have made him a respected figure on the council. But critics wonder if some of those same qualities might also spell disaster if Potter becomes the leader of the county; they wonder about his ability to delegate authority, to get things done quickly, "to see the big picture."

"I would envision the county government just stopping as Neal personally went into things for days, months," said Robert McGarry, the county transportation director who has known Potter since 1977.

Often called "the elder statesman of Montgomery County politics" and "a walking encyclopedia" of county facts, Potter has long possessed an image that does not fit that of the standard politician. He often seems a character from the past: tall, lean, gentlemanly, polite, with a professorial habit of taking young, like-minded politicians under his wing and an apparent lack of interest in whether his shoes match his suit. When he eats dinner, often late in the evening, he frequently listens to a recording of bird calls.

Asked to name his favorite book, he replies the county budget books, "a new one every year."

For decades, one of his guiding interests has been the World Federalist Association, an organization that works for international peace, and his reputation has been that of the conscience of the County Council, owing to his efforts to make sure residents are always heard.

Tuesday's primary comes at a time when Montgomery County, with 750,816 residents, has become the most populous jurisdiction in Maryland, still largely Democratic, with a squeaky-clean image for good government, efficient services and a minimum of nasty political fights.

Although Potter is identified with several issues that have bolstered Montgomery's progressive image -- preserving the county's diminishing farmland and planning for its long-range transportation needs -- his position lately on the council has been, as one critic described it, "the great dissenter." Indeed, Potter's disappointments over failing to pass a development tax and failing to curb what he terms "the excessive development" proposed for downtown Silver Spring contributed to his January announcement that he was retiring. A series of public accolades followed.

Hours before the filing deadline in July, however, Potter entered the campaign for county executive, casting himself as a slow-growth candidate and saying that he believed the voters needed a choice. Detractors questioned his motivation for entering the race, contending that Potter was never in fact as anti-growth as he now says he is and pointing to the behind-the-scenes influence of backers such as State's Attorney Andrew L. Sonner, a longtime Kramer foe.

"Neal is running because he's being used," said Rose Crenca, who has served with Potter on the council since 1978 and is running on the Kramer slate. "There are a lot of people who want to be county executive and either missed their opportunity in the past, or don't want to spend the money . . . . Neal feels it's his duty to respond to the people who want him to run, who are saying, 'We need you, Neal, to run against that bad, bad, bad Sid Kramer.' "

At times, Potter has seemed uncomfortable in the spotlight, less forceful in voice and manner than Kramer and leading some to question his commitment to the race and whether he really wants to be county executive.

Characteristically, Potter has remained calm in the face of such criticism, and he also appears unruffled by suggestions that he is risking ending his public career on a sad note -- trading barbs with Kramer and exiting in defeat.

"I'm not particularly interested," he said with a smile, "in how I fade into the sunset."

It would not surprise people who know Potter that he is the author of a book entitled, "Trends in Natural Resource Commodities." They might be surprised to learn that he is also a skilled tractor mechanic.

Alfred Neal Potter grew up on a small Montgomery County farm near the District line, where the Capital Beltway now crosses the Clara Barton Parkway. In 1961, government authorities informed his aged parents that the bulk of their land would be needed within 30 days for the new ring road around Washington. The trauma of that news, Potter contends, led to the death of both his father and his mother within a few months.

"That, to me, demonstrated the terrible importance of government planning ahead so that they didn't just come in and say, 'We're taking your farm,' " Potter said. "You have to avoid running over people and the environment."

Potter's regard for the rural way of life would surface years later as he successfully pushed for legislation concerning the preservation of farmland and scenic country roads. No longer responsible for a tractor, he still delights in working on his red Toyota, figuring out how to get the ultimate mileage from the car and drawing diagrams to show colleagues why their own vehicles might be stalling.

At Bethesda-Chevy Chase High School, Potter made an impression on Marion Esch, who sat behind him in history class, with his vast knowledge of American history. ("He knew more than the teacher," she said.) They were married 50 years ago, after Potter had completed studies in economics at Johns Hopkins University, the University of Minnesota and the University of Chicago, producing a master's thesis on "Capital Gains Taxation in the Federal Income Tax."

There followed jobs with the Office of Price Administration, with Potter commuting by bicycle from Chevy Chase to downtown Washington; Americans United for World Organization, after "the atomic bomb clearly changed the world immensely"; teaching economics at what is now Carnegie-Mellon University; and again at Washington State University, where Potter became state president of the World Federalists.

"The World Federalists raised some money and put me on the road for two years," he said. "I talked to Rotary Clubs, churches, telling them of the situation of the world. It was very clear we couldn't maintain peace unless we had a world organization adequate to enforce disarmament." A highlight of those years -- and indeed, his career, he said -- was his successful work in persuading voters in Idaho to elect a woman to Congress for the first time in the early 1950s.

But a family tragedy intervened to end the Potters' years in the Pacific Northwest. The younger of their two daughters, Freda May, was found to have leukemia in 1954 and the family returned to Montgomery County so she could receive treatment at the National Institutes of Health. She died within eight months. "It was terrible," Potter said.

He soon took a job with Resources for the Future Inc., a Ford Foundation agency, looking into the history and the scarcity of natural resources. One mission took him to Antarctica for three months, a journey he considers another of the highlights of his life.

But the event that would have the most impact on the next three decades of his life was a gathering at the county's old Western Suburban Democratic Club in 1958, and a speech by Margaret C. Schweinhaut, who now represents the county in the state Senate.

"What got me started," he said, "was a little speech by Peg . . . . attacking bosses in Montgomery County. That speech electrified me."

In the last stage of his career, Neal Potter is trying to be the politician he has never been -- or perhaps, never had to be.

On a day-to-day level, there is the pressure of actually mounting a campaign -- leafleting at Metro stops, facing off with Kramer in debates, helping to mail literature to 75,000 voters. In the last several council elections, Potter faced only nominal opposition and became a leading vote-getter among the council members with minimal effort.

In a highly publicized campaign with Kramer as a formidable opponent, Potter also has been placed in the unfamiliar position of having to explain certain inconsistencies in his statements and his record.

Criticizing Kramer for his coziness with developers, he has also left himself open to an examination of his own council votes that shows that he also has had a hand in the county's recent rapid growth. After charging Kramer with "political bossism" for creating the Kramer slate, he turned around and endorsed his own slate of candidates. He said he would accept no money from political action committees, yet, recent campaign fund reports showed that he accepted $200 from a psychiatric group. Potter said he couldn't see that it represented any special interests.

For the first time in a long time, Neal Potter has had to explain himself, instead of seeking explanations, as he so often did, from others.

"I'm comfortable with that," he said calmly. "If I get my message across, I think I will actually win."

Age: 75.

Birthplace: Montgomery County.

Education: Montgomery County Schools; Johns Hopkins University, 1933-35; University of Minnesota, 1935-39; University of Chicago, 1940. Master's degree in economics.

Work Experience: Worked as head of the income analysis unit at the federal Office of Price Administration; served as administrative director of Americans United for World Organization; taught economics at what is now Carnegie-Mellon University and Washington State University; served as field director for the World Federalist Association; worked as research economist for Resources for the Future Inc.

Civic and Professional Associations: Past president of Montgomery County Planning Association; past president of Metropolitan Council of Governments; past co-chairman of Metropolitan Washington Coalition for Clean Air; a national vice president of the World Federalist Association.

Religious Affiliation: Methodist.

Marital Status: Married; one daughter, one grandchild.

Favorite Reading: The county budget book. STAND ON KEY ISSUES

Trolley: Voted last year to support the use of state funds for construction of a light rail between Silver Spring and Bethesda, but now advocates delay of project.

Silver Spring Redevelopment: Opposes a planned regional shopping mall for downtown, but supports a smaller-scale revitalization.

Taxes: Supported a countywide development tax and parking tax and advocated increases in county beverage and energy taxes. Also supports a local gasoline tax.

Charter Amendments: Supports a compromise proposal to limit property taxes to the rate of inflation.