It should have been the crowning moment for Gov. Marvin Mandel - that election night of 1974 when his family and closest associates jammed into a Baltimore hotel suite, toasting the man who had just racked up the largest plurality in Maryland history.

But while his followers clinked glasses, Mandel sat alone in a corner of the room, his stocking feet elevated, watching television. He seemed to be in a gloomy, cranky mood, detached from the party.

Mandel has since said he "knew" as far back as that night that he was the ultimate target of the federal investigation that eventually led to his conviction on political corruption charges last August and suspension from office more than a year before his term expired.

HE could not have known then that with his conviction, an era of certainty in Maryland politics also would end.A coalition of political clubs and monied interests that had dominated statewide politics - with only momentaryinterruptions - since Theodore E. McKeldine became governor in 1951 - no longer has an automatic hold on the governor's mansion.

That loose coalition, led most recently by Mandel, left behind no heir apparent to the convicted governor, only six Democrats and four Republicans running in as many directions for their parties' nominations in the September primary.

For the first time in a dozen years, serious candidates are actively competing in the governor's race.

"By now," said Barbara Mandel, the suspended governor's former wife, "Marvin always had a unified ticket - all the money and the backing. It was exciting. It was wonderful to go in without a real opponent. It made campaigning great fun."

"Everything used to be set by now," said John Hanson Briscoe, speaker of the Maryland House of Delegates. "The tickets were pretty much made up. The organizations were in line and the money was raised. There's certainly more flux this year than I've ever seen."

No one knows yet what will take the place of the Mandel method. Gubernatorial candidates are trying out new campaigning techniques such as issuing detailed position papers on economic development, searching out volunteers in the hills of Western Maryland and leaving local elctions in the province of the local citizenry.

The thousands of candidates who have filed for the 800 other positions up for reelection - from county executives to orphan court judges - have not felt the influence of the political hierarchy so common in previous elections." With (state Senate president) Steny Hoyer running for governor and Pete O'Malley (Prince George's county political leader) concentrating on that we've had fewer leaders wanting a say about who ends up on the slate," said an aide to Prince George's County Executive Winfield M. Kelly Jr., a top Democrat in the county party.

Montgomery County also has a favorite son in the gubernatorial race, Acting Gov. Blair Lee III. Democrats and Republicans there are caught up in their county-level races - county executive, House of Delegates, State Senate and Congress - and generally have stayed neutral about the gubernatorial race, for now.

Few traditions are surviving this statewide election campaign. The Baltimore approach to elections is fading. Talk of political clubs, walk-around money and fund-raising giants like Irvin Kovens, Mandel's millionaire friend, is beign replaced with conversations about "media-saturation campaigns," the cramp of the new $1,000 limit on contributions, the importance of grass-roots volunteers and the Washington suburbs.

The six Democratic gubernatorial candidates - Lee, Hoyer, Baltimore County Executive Theodore G. Venetoulis, Attorney General Francis B. Burch, Baltimore City Council President Walter S. Orlinsky and former State Transportation Secretary Harry R. Hughes - have been crowded into a candidate forum only once and then they could find little to debate among themselves. They sat together like reformed schoolboys agreeing that honesty and ethical government must replace the old Maryland politics that stained a governor, a former vice president and two county executives with politican corruption.

Richard Schifter, one leader of the Democratic Party in Montgomery County, believes the old politics passed away before this campaign. "Political machines ain't what they used to be . . . I don't think they ever delivered much anyway," he said.

"The people will vote along social group lines, not political clubs. If you make a good presentation to the local bar association. then the lawyers will talk among themselves. It's the same with teachers, oly Name Societies, active Jewish groups. That's how the word is passed around now," Shifter said.

In 1970 and 1974 the word spread long before the primary campaign began. Then the Mandel group stunted any competition by currying the support of local political figures across the state and tying up all the campaign funds a year up all the campaign funds a year before the primary. Mandel took care of the political support. He had been a member of the General Assmebly 17 years before he became governor and many leaders recognized Mandel's friendship and power in pushing through their favorite legislation.

Kovens managed the money.

Working out of an office at his family's discount furniture store in down-town Baltimore, Kovens would secure tens of thousands of dollars for Mandel's campaign network with a few days of telephone calls to some 125 contributers.

Kovens also made fund raisers an art form in Maryland politics. In 1969 his first gubernatorial gala for Mandel brought in $600,000. In 1970 he put on a "Four Star Salute" that raised almost $1 million and frightened away any serious contenders for the next year's primary.

For this election, computers are doing the fund raising and Kovens is sitting in his office far more concerned about the pending appeal on his political corruption conviction with Mandel and four other men than the budding state campaign.

On the advice of his attorney, the silver-haired millionaire refuses to discuss politics.

Friends of Kovens say he is preoccupied (some say "obsessed") with only one statewide race: the campaign for attorney general.

In post statewide elections, the office of attorney general has fallen neatly into the lap of the dominant political organization, so neatly that no one serious ever opposed the leaderships choice.

This year the strongest (and so for the only) Democratic candidate is Stephen H. Sachs, who as U.S. attorney in Baltimore during the late '60s pursued political corruption with a zeal that became a tradition in the office.

Sachs was the mentor of Barnet D. Skolnik, the assistant federal prosecutor who powered the investigation and conviction of Mandel and his codefendants. As such, he is openly despised by Mandel and Kovens. "I kicked them when they were up," says Sachs of the old guard politicans. "Iknow I stepped on their toes and they'll find a candidate to oppose me."

Nothing better illustrates how much the rules of the game have changed than the fact that so far, no candidate has been found to take on Sachs, despite Kovens' efforts. In fact, most of the gubernatorial candidates currently expect to leave their tickets open in the spot market attorney general, giving Sachs a free ride to office.

The media battle has yet to begin in earnest. Before that time, some of the candidates are expected to drop down to the lieutenant governor's position on other tickets. Hoyer and Lee are currently negotiating the terms of such a berger.

Only three, little known Republicans have declared for their party's gubernatorial nomination: John W. Hardwicke, a Harford County lawyer; Donald Devine, a University of Maryland professor of political science, and Carlton Beall, a former Prince George's County sheriff.

Anne Arundel County Exdcutive Robert A. Pascal, a popular Republican and born-again Christian, has said he will consider running if he is assured that the party will help him raise campaign funds. Earlier this year, in a closed-door meeting with Republican legisative leaders, Pascal said he would like to run but he did not want to make the compromises he feared would be necessary to run for governor in Maryland.

That pressure to find money within the new restrictions of the $1,000 contribution limit has forced all candidates to reexamine how to wage their campaigns. Ventoulis, in his "New Maryland" campaign, has sidestepped the old political clubs and built a voluntary organization from the ground up throughout Maryland.

"We decided we would raise only $400,000 for the primary," said Venetoulis. Then he paused, saying "only $400,000' sound strange, doesn't it."

Lee plans to spend $500,000 alone on his "media package," according to Frank A. DeDilippo, Mandel's former chief of staff and now and advertising executive and campaign consultant to Lee. "It's the new way of campaigning. On one night of TV saturation on every channel, you can reach the whole constituency," DeFilippo said.

What is new for Maryland is old hat for the rest of the country. The collective campaign fundsof all the democrats is more than $1 million already and much of that money will be spent to broadcast their political advertisements. DeFilippo calls this the new "media dual."

However they spend their money, or how many position papers they compose, the candidates will be facing an electorate relatively unstudied over the past 12 years. The candidates all say they are reexamining the geography of the state, attempting to discover what Western Maryland, the Eastern Shore or the Baltimore dock-workers expect and want from a governor.

"I think the issue will finally come down to whether you can run the executive branch of government," Schifter said. "They will talk about ethics and honesty but I don't think that there is a real question about the ethics of any of the candidates."

At the county level, Democrats and Republicans are finding the same theme in their campaings. It is a different local-level race than the 1974 election. That was the year of redistricting when seats were added to the House of Delegates for Montgomery and Prince George's.

In Prince George's, the Democrats put together a "blue ribbon" slate that swept all but a few primary seats and, in the general race, did not lose a seat to a Republican. "There are a lot more room, then, it was a matter of finding good people rather than now, which is more like cleaning up house," a Kelly spokesman said.

O'Malley, a Democratic leader in Prince George's and key campaign adviser for Hoyer, claimed that this would be the year that the country organization proves its worth. "Democrats were successful in the 1974 election but they've been even more successful working together since they've been in office . . . Can they hold together and move towards quality or will they be lazy?"