ANNAPOLIS -- Six years ago, Brad Davidson, a gangling, 25-year-old novice, surprised Annapolis politicians by winning a seat on the City Council. Many called the youngest alderman in Annapolis history a "boy wonder" and predicted a brilliant political future for him.

Last week, Davidson surprised many residents here by resigning his council seat and stepping away from elected politics to become chairman of the Maryland Commission on the State Capital.

To many people, it seemed a strange job for a man with political ambitions, because the commission, which monitors the development and preservation of Annapolis, has been most noteworthy in recent years for its lack of action and members' poor attendance.

Yet the move has sparked speculation among local politicians about whether Davidson is plotting a new, more stunning political initiative or whether he has given up his political career at the tender age of 31.

Davidson, a stockbroker whose family made a fortune in the molasses trade and the Welch's Grape Juice Co., invariably describes himself with self-deprecating humor and said the answer is in between.

He insists that he is still interested in politics but that he has accomplished much of what he wanted as an alderman -- including keeping Eastport Elementary School open and preserving the area's residential character and marine industries. He said he has no immediate plans to run for office.

Davidson characterized the commission post as "a step up" for him, and he said he would not have taken the job if he did not believe he could revitalize the panel. It would be the ideal body, he said, to tackle longstanding problems such as property tax and annexation disputes between the city and the county, as well as regional issues such as transportation and development.

"It really has great potential," he said. "It's just a matter of the chairman using good judgment and energy to galvanize this group into action."

Some observers say they have seen sure signs that Davidson's political career is waning. Last fall, they noted, he ran for a seat on the County Council and was badly beaten -- even in his home ward of Eastport -- by incumbent Maureen Lamb. This summer, after the birth of his first child, Teddy, some City Council members complained that he was losing interest and missing committee meetings. At the same time, a longstanding alliance with Mayor Dennis Callahan broke up in a series of disputes, with the mayor publicly calling for Davidson to resign.

"At one time, Brad was viewed as a very ambitious young politician," said Alderman Carl Snowden, who called Davidson one of the more intelligent council members. "I'm not sure the fire is still there as it relates to running for public office, going through the process of being accepted or rejected. It's tough to be rejected, and not everybody has what it takes -- the stamina and the desire to go through with it all."

But others say Davidson has made a shrewd political move. The commission is dormant but could become important if it is whipped into shape, they said. And its members -- who include the governor, state house leaders, the Anne Arundel County executive, the Annapolis mayor, the superintendent of the U.S. Naval Academy and several area legislators -- could become powerful allies for an aspiring politician.

"Personally, I think that he's looking far ahead," said Annapolis Alderman Samuel Gilmer, who said he suspects Davidson may be plotting a race for mayor in 1989. "Strangely enough, very few aldermen have ever succeeded to any higher form of government office once they serve on the council. There's no mayor that's ever gone any farther than being mayor. Now he's stepping into a state situation, and I think he's going to make himself very visible . . . . "

Davidson acknowledges that his confidence was shaken by his recent setbacks, including the unsuccessful race for County Council.

After winning a City Council seat at an early age, he was overconfident, he said. "I thought I'd be on the County Council, and who knows, I'd be county executive. That's what got me in trouble -- running for a seat because it was my plan. But it didn't comport with reality.

"But it was necessary in my development as a politician," he added. "I had a false view of what I could accomplish before that loss . . . . It was a necessary experience. I'm glad I got it out of the way now while I'm still young."

Indeed, Davidson's own rendition of his history shows the importance of taking opportunities.

Davidson said he graduated from St. John's College -- "I couldn't get in anywhere else" -- with "no marketable skills in anything. I went to work for my brother-in-law, an agricultural economist in D.C., for about two months. Actually, he didn't give me any work; he just gave me a desk and a chair and a phone. I went out and got a job on Capitol Hill with . . . {Rep. E. (Kika) de la Garza (D-Tex.)}. He hired me because he needed a white person. He had too many Hispanics on his staff and was taking heat from his constituents. I wasn't qualified to do anything, but I was white."

After working there 1 1/2 years "writing letters and helping people with Social Security claims," he said, "I got bored. I decided to join the National Guard . . . . I was thinking I might want to get involved in politics, and I wanted military credentials."

Davidson has since transferred to the Army Reserve, where he is an infantry lieutenant.

Although Davidson has taken himself out of the immediate political circle, he admits to keeping an attentive eye on the arena. Indeed, he has assigned himself the task of getting his chosen candidate, former Eastport Civic Association president Lynn Hamm, selected by the city's Democratic Central Committee and City Council to replace him.

"I think I've got a lot to offer," Davidson said. "I enjoy politics, and I know there are going to be other opportunities in the future for me to make an impact. I'm by no means wilting away."