The time had come for Harry Hughes to call an emergency meeting of his principal advisers and supporters. It was late June, his campaign treasury was bare, his showing in polls dismal and he was trying to decide if he should stay in the race for governor of Maryland.

A dozen men sat around a small circle in the Baltimore living room of a campaign aide.They listened to Hughes recite the gloomy facts and then to a man, encouraged him to remain in the Democratic primary that he eventually won in a stunning upset Sept. 12.

"It was a critical meeting for Harry," recalled Joseph Coale, who managed Hughes' primary campaign. "If they had said, "No, we're not going to support you' or 'You made a good shot at it but you're not getting off the ground,' we wouldn't be here today."

The men who gave Huges the reassurance he needed in the dark days of June formed his campaign family, the inner circle of fund raisers, aides and strategists who helped him overcome his early recognition problems and then persuade voters his could win.

They include his closest personal friends and longtime professional associates, men who continue to guide his general election campaign today and who would play an important role in a Hughes administration if he beats his Republican opponents, J. Glenn Beall, Nov. 7.

The people around Harry Hughes are not normally associated with politics in Maryland. Most of them belong to an occupational and social class that traditionally devotes its energies to civic and cultural rather than political causes. Few have ever before participated in a political campaign. Many look down on politics as a dirty business.

They offer a sharp contrast to the last ruling Democratic crowd. Marvin Mandel, the preeminent Maryland Democrat until he was convinced of political corruption and stepped down from office last year, surrounded himself with a colorful retinue of rough-talking politicians, business entrepreneurs, lobbyists and insurance tycoons. They dined at expensive restaurants, vacationed in Ocean City and Florida condominiums, playeed the horses, went deep sea fishing and always contributed to Democratic causes.

Hughes' chief backers and aides come from a very different world. They represent the business and social elite of Baltimore, men who serve on the boards of large corporations, prestigious lawyers, stockbrokes and bankers. They head blue-ribbon commissions and are visible in probusiness organizations and local charity.

They come from old Maryland families with old money and live in Baltimore's ritzy Roland Park and Homeland or the outlying horse country. They support the Baltimore symphony and museums, relax at the exclusive Greenspring Club and Maryland Club, hunt ducks and play squash. Instead of Democratic clubs, many belong to Ducks Unlimited, a national organization t conserve wild fowl.

The Hughes campaign provided on-the-job political training for many of them. When Alonzo G. Decker Jr., chairman of the board of a power tool manufacturing firm, agreed to head a fund-raising drive last spring, he compiled a list of persons to sell tickets for the affair. Instead of sending each person the the customary 10 or 20 tickets to sell, he thought he was supposed to enclose one ticket per envelope.

After a lifetime of isolation from Maryland politics, Hughes' intimates say they were attracted to the Democratic nominee because of his moderation, his reputation for integrity and his independence from the old-line political system that has produced more than a decade of scandal in Maryland. They view Harry Hughes as a kindred soul.

"I don't think Harry has ever done anything in his life that would frighen the establishment," explained Francis D. Murnaghan Jr., a leading Baltimore lawyer who serves as an honorary campaign chairman. "With Harry, there just isn't that sense that he's threat . . . it makes it easy for those people to support him."

Hughes, 51, is a private man, described by his friends as an independent, deliberate thinker who seeks different points of view before reaching a decision. He chooses special advisers for special matters, asking them for alternative courses rather than set solutions.

When he looks for advice, he reaches beyond his associates in the closeknit Baltimore "establishment." His entourage includes friends from his native Eastern Shore, former colleagues in the state legislature and men who worked for him when he was Maryland transportation secretary from 1970 to 1977.

Hughes has a two-tier structure of campaign advisers. At one level are the blue-chip businessmen and professionals, such as Decker and Murnaghan, who raise funds, provide advice, hold parties and campaign within their own circles for Hughes. They form the "Hughes for Governor Committee" and meet regularly to discuss the campaign.

The second tier includes Hughes' full-time campaign aides, who handle day-to-day chores of scheduling, formulating strategy, briefing the candidate, preparing his position papers and coordinating fund-raising activities. They are younger than most members of the "Hughes for Governor Committee" although they come from similar social and professional backgrounds. All are political neopytes.

Campaign manager Michael F. Canning, a public relations specialist from Bowie, and J. Michael McWilliams, a lawyer in a prestigious Baltimore firm who coordinates fund raising, are considered Hughes' principal campaign aides.

The two are trusted and loyal friends who worked for Hughes at the Department of Transportation and were impressed with him when he resigned as transportation secretary in protest over alleged tampering with a Baltimore subway contract.

Canning, 40, and McWilliams, 39, formed the inner circle at DOT along with the late Joseph Dore, who served as a special assistant to Hughes. The four men met almost daily after work in Hughes' office or a nearby bar at the Friendship Hotel and talked about business and personal matters. Among the topics was Hughes' political career.

In the loneliest days of Hughes' uphill primary fight, when no one took his candidancy seriously, Canning and McWilliams were pitching in at considerable personal sacrifice. CCanning quite his state job to join the campaign. McWilliams took away time from his law practice, lent Hughes $16,500 for the first wave of television spots, and underwrote part of another $25,000 loan in the final week of the campaign.

McWilliams' back porch in Baltimore's Roland Park area became an unofficial clubhouse for Hughes' brain trust during the primary. The Democratic candidate would often end a day of campaigning with a drink or meal at McWilliams' home, followed by a review of the campaign's progress. "It got to the point," said McWilliams, "where my wife started cooking for three."

When Hughes' lieutenant governor running mate, Samuel W. Bogley III, announced two weeks ago that he might withdraw from the ticket because he disagreed with Hughes on state funding of abortions, the Democratic nominee called in Canning and McWilliams to help avert a campaign crisis. Canning drafted the statement resolving their differences after a five-hour negotiating session.

A third key Hughes aide who helped smooth out the Bogley problem was Joseph M. Coal III, a stockbroker from Baltimore, who managed Hughes primary campaign, and in the early stages served as a one-man organization with responsibility for fund raising, media, scheduling and strategy. Now he serves as advance man and head of scheduling.

As the first fulltime campaign stafter, Coale, 33, developed a close personal and working relationship with Hughes. The two seemed almost inseparable during the primary as they spend grueling 18-hour campaign days touring the state together. They learned to buoy each other's spirits when they were the only ones to show up for a scheduled campaign event.

"I often felt like Harpo Marx," Coale recalled. "In the left pocket I had a big pack of volunteer cards. On the right side of the jacket, I had the (campaign) buttons. Then I had bumper stickers on the right side of my pants."

On of Coale's most significant contributions was helping Hughes improve his television manner. They spoke to a consultant who once coached Richard Nixon and practiced Hughes' delivery in a Baltimore television studio twice a week for several weeks. The work paid off when Hughes performed well in a series of primary television debates.