It was a rare sight in East Baltimore in 1971: a woman, voluble and barely five feet tall, stalking the neighborhood in a bid for the City Council.

One day she saw a group of old men in a shopping area, "and I went up and started to give out my literature and they said, 'Why aren't you home doing your wash?' And I said, 'I don't think that's the basis of this campaign.' "

But they continued, and so candidate Barbara Ann Mikulski thought a minute and said, " 'Look, I want to be elected, but not at the sacrifice of my dignity. Give me back my literature.' And I took my literature back and I walked away."

If Mikulski, now a five-term member of Congress who is running for the U.S. Senate, likes the story, she likes the epilogue even more: About a year after her election to the council, one of the men took a bus to City Hall to see her. According to Mikulski, he said, "Boy, was I wrong. I think you're doing a great job and I want to apologize. And if you ever need any help . . . . "

That is vintage Mikulski, according to her supporters: feisty, proud and opinionated, yet eager to build a bridge where ever possible. Underestimated in recent months by those who wondered whether a tart-tongued social reformer could make a credible bid for the U.S. Senate, Mikulski has surprised the doubters. Early polls show her with a wide early lead over each of her Democratic rivals, including Gov. Harry Hughes, Rep. Michael D. Barnes of Montgomery County and Baltimore County Executive Donald Hutchinson.

"She has the oomph to do it," said state Del. Elijah Cummings (D-Baltimore), a lawyer and chairman of the state's legislative black caucus, at a Mikulski fund raiser in October. It was attended by developers, union officials and neighborhood friends. "She's never forgotten where she came from, and that's a very attractive quality in a candidate," Cummings added.

Mikulski said in a recent interview: "I'm not afraid to take risks. I mean, all my life people have been cautioning me against the risks. And I carefully analyze them, but really my candidacy was based on consultation with those community people about would they support me, did they want me, and they said, 'you bet!'

"And then, by the way, when I won, I made my peace and formed my alliance with the existing political structures. I wanted to be sure I would have the alliances within the City Council to accomplish the legislative agenda that I campaigned on . . . . [I did that by] working hard and being cooperative and identifying mutual needs between us."

In an age of painful introspection for many Democrats, when they wonder whether their programs have gone too far and produced too little, Mikulski, 49, a former social worker who specialized in community organizing, has kept the faith. Although she represents a diverse metropolitan Baltimore district whose white neighborhoods supported President Reagan in 1984, she campaigned vigorously for Walter Mondale and served as national cochair of his campaign.

Over the years she has continued to support the Equal Rights Amendment, abortion rights, protection for abused children, aid to battered women, Social Security and domestic content legislation favored by auto workers. Last week she was part of the House minority that voted against the balanced budget legislation and the majority that derailed the tax revision measure, in part because it would have increased taxes on the pensions of federal workers, a key constituent group.

She began her political career by defying the local political organization and running for City Council in 1971, where she served until 1976. In 1974 she ran unsuccessfully for the Senate against incumbent Charles Mac. Mathias Jr., a Republican. In 1976 she won her congressional seat, where she now represents a district including ethnic East Baltimore, predominantly black Cherry Hill, the middle-class northeast section of the city and the suburban communities of Towson, Pikesville and Columbia.

Although challengers have sought to portray her as out of step with the values of her constituents, Mikulski has been reelected with large margins throughout the district.

Through the years she has perfected a rousing rhetorical style marked by an outrage that seems as fresh as it was in 1970, when she organized her Baltimore neighbors to stop a 16-lane expressway planned to cut through their community.

"Imports are killing us," she told delegates to a state AFL-CIO convention this fall. "Then when times get rough, corporate executives say it is the American workers' fault. They see you as the problem . . . . When you have corporate executives who can deduct two martinis for lunch telling Esskay a meat-packing plant workers to give up their lunch money . . . , Barb Mikulski says it's time to stop the givebacks and start the get-backs."

She can be brusque: Asked her strategy for capturing a winning share of the statewide vote, she snapped, "I'm not going to lay out my strategy for The Washington Post."

Her friends and detractors attribute her reputation to a quick, quotable wit, strong stands and hard work for her constituents. She has, for example, fought for federal funds to dredge the port of Baltimore.

Supporter Frank Lidinsky sums it up. He said he first noticed her when she knocked on his parents' East Baltimore door during her City Council race. "She was one of the first to come around and hit the doors asking for support," he said, noting a contrast to the clubhouse style more common in a neighborhood where ethnic ties ran strong.

Her critics say that she can be unnecessarily acerbic, as when she visited Baltimore County Del. John Arnick, generally a supporter, on a courtesy call and said, he recalled, "John, we've been friends for years." Then she paused and added, "No, we're not. We're not friends, are we? We've worked together but . . . . "

Del. Paul Weisengoff, a traditional Democratic organization politician from South Baltimore who said he can vote both sides of an issue, believes that she is "a competent, capable lady, a pro-city advocate . . . . But she's more liberal than I am; it's just a general liberal attitude. Campaigning for Mondale hurt her in my district. My district's not a liberal district, it's blue collar."

Her style sets up an interesting contrast with her rival Senate candidate from the Baltimore area, Baltimore County Executive Hutchinson, who for years carried a reputation as a moderate-to-liberal politician but is positioning himself as a conservative for this campaign. He has set about wooing the rural Western and Eastern Shore areas under the theory that all of his rivals are too liberal to win support there.

But even there, according to Rep. Roy Dyson (D), who represents the Eastern Shore, Mikulski is winning support. "If the election were held today, Barbara would win there," he said. "Barbara is well known and it's positive."

A November Baltimore Sun poll of likely Democratic voters showed Mikulski with 38 percent of the vote, compared to 18 percent for Hughes, 16 percent for Barnes, 8 percent for Hutchinson and 20 percent undecided.

"I don't think her constituents think of her as either liberal or conservative," said Arnick. "She's just a feisty broad -- I mean character -- and they like that."

"It is my sense of strategy that you need to have alliances," Mikulski said. "One person can make a difference, but a group can make a change. An alliance can make a change. And I understand power."

In the weeks since her announcement she has been quietly touching base with the political establishment in Baltimore and the suburbs, and, in traditional establishment fashion eschewed so far by most of her Senate opponents, refusing to say exactly when and with whom. She spends days on the telephone rounding up funds: her campaign office said she has raised about $300,000, and powerful House Energy and Commerce Committee Chairman John Dingell (D-Mich.) will host a fund raiser for her in Bethesda this winter. She spends evenings making the rounds of civic and community groups.

"I think I bring a new energy, new ideas and a new spirit to the United States Senate," she said, "And they'll know if they get Barb Mikulski, they'll get a senator with her heart in it."