While at least half dozen Democrats are jockeying for support as Democratic candidates for governor, one man who has his sights set on a lesser goal may play a key role in the 1978 Maryland Democratic primary.

Former U.S. Attorney Stephen Sachs is running full stream for attorney general and issuing a warning that "attroneys who are running for governor with the idea of dropping back (and becoming candidates for attorney general) will have to face Steve Sachs."

It is a formidable message, for Sachs has been on the stump since last November, and already has raised $122,000 more than most of the active candidates for governor have in their campaign coffers, with the primary still more than a year off.

Sachs is telling audiences all over the state that the office of attorney general "shouldn't be a consolation prize" accepted by lawyers only after they have faltered in their quest for nomination as governor or lieutenant governor.

With the end of Gov. Marvin Mandel's political corruption trial now in sight, Sachs, who is the only announced candidate for any statewide office other than governor, is considered a hot item as a possible ticket mate by gubernatorial hopefuls who see corruption as the main issue next year.

The 43-year-old Sachs is setting the tone for a reform campaign by reciting a list of public officials brought to justice during his years as a federal prosecutor: a Prince George's County commissioner, a speaker of the Maryland House of Delegates, an Eastern Shore congressman, and a U.S. Senator.

Along with Mandel and his five codefendants, Maryland's political tradition is again on trial in the federal courthouse in Baltimore. At the heart of the prosecutors' case is the allegation that Mandel accepted "a flow of financial favors" from friends and politival associates in exchange for political decisions that benefited those friends and associates. Among the other defendants is Irvin Kovens, the state's premier political fund raiser, whose money skills have helped elect mayors and governors in Maryland for decades.

Even with Maryland's political establishment at the dock, the two leading candidates for governor today are those most closely associated with Mandel and big money politics: Acting Gov. Blair Lee III and Attorney General Francis B. Burch.

With the Mandel era ending, either with a guilty verdict or at the end of his term next year, Maryland voters already are being deluged with appeals for support by a potpourri of contenders for what promises to be the most wide open race in years.

The road to Ocean City already is lined with billboards and bumper stickers boosting the nascent gubernatorial campaigns of Lee, Burch, Baltimore County Executive Theodore G. Venetoulis, State Senate President Steny H. Hoyer, Baltimore Mayor William Donald Schaefer and City Council president Walter S. Orlinsky, and the ever-present attorney general candidate Sachs.

Sachs is challeging what he says has been "an absolutely unvariable tradition" that nominees for attorney general have been dropouts from the governor's race, selected to balance the ticket on the basis of ethnic, ideological or geographic considerations.

As a result, Sachs said, the office has been "a side order, the french fries that go along with the Big Mac."

Because such criteria make the nominee for the top legal office part of "the team," Sachs said, attorneys general have been "muted" because "they have been part of the club." While he doesn't suggest that such clubiness has resulted in wrongdoing, Sachs said he believes that Burch has suffered from "timidity" in initiating ivestigations of fellow state officials.

The attorney general should be "more than a Stephen Fetchit. He has a profound responsiblity to be the best the law has to offer," Sachs added.

On the guvernatorial front, whatever happens to Mandel, Lee figures he will benefit. If Mandel is acquitted and his health permits him to resume an active role as governor, Lee will revert to lieutenant governor and have more time to devote to putting together a formal campaign. If Mandel is found guilty, Lee will become governor in fact and inherit all the benefits of incumbency.

Lee has tried to divorce himself from the corruption issue in the Mandel administration by making a distinction between Mandel "the good governor," (recently toned down by Lee to "a fairly good governor") and Mandel the man "who has had some personal problems.

Lee nonetheless has enlisted the support of some key. Mandel advisers, notably Frank deFilippo, Mandel's former chief of staff. DeFilippo now is president of the Rosenbush Advertising Agency, which Lee has hired to direct his media campaign.

By dint of his long years in office and early fund-raising success, Maryland's three term attorney general, "Bill" Burch, is counted a top gubernational contender at this stage of the race.

While he has remained generally independant of the Annapolis setting, Burch's membership on Mandel's past two statewide tickets and his courtship of loyal Mandel money men are expected by political sources to create an "image problem" for the attorney general.

Burch downplays the importance of the corruption issue, saying thhe electorate is more concerned with experience and ability than "negativism" and "cutting other people up."

The candidate who plans to make th most of the corruption issue is Venetoulis, the 43-year-old, first-term executive of Baltimore County.

AS an independent politican with three scandal-free as head of one of Maryland's most populous and traditionally corrupt subdivisions, Venetoulis is expected to campaign as a reform candidate unfettered by big money and Annapolis deals.

Political sources list as his chief liabilities a lack of recognition outside the Baltimore area and a shaky base at home where he does not get along with other elected officials and is perceived in some circles as a "lightweight."

Another reformer, ex-Transportation Secretary Harry R. Hughes, announced Friday he will campaign on a "clean government theme." Hughes' protest resignation from the Mandel administration in May makes him the Elliot Richardson of Maryland politics and a contender for lower slots on someone else's ticket, according to some political sources.

The non-Annapolis politician - Baltimore Mayor Schaefer - given the best chance of winning has shown the least interest in becoming governor. Despite polls showing him as the man to beat, Schaefer is taking a "wait-and-see" stance.

Schaefer's wide popularity in Maryland's biggest political subdivision is only part of his strength as a possible candidate. He also is the only "outsider" who has access to traditional sources of campaign money, having relied on Kovens in the past to raise money for his campaigns.

Orlinsky, 39, Sachefer's political arch-enemy, is exhaustively touring the state to gain exposure with voters outside the Baltimore area. As if to prove his seriousness as a candidate, the energetic Orlinsky has called newspaper editors and forced them to listen to an hour-by-hour account of his political peregrinations.

Hoyer, who also has been pursuing a frantic daily schedule since early this year, is the gubernatorial candidate who might be hurt most by Sach's agressive bid to wrap up the nomination for attorney general. For if Sachs manages to avoid tradition, an unsuccessful Hoyer gubernatorial candidacy would leave the Prince George's County senator no chance to run to attorney general.

As the youngest of the candidates, at 38. Hoyer has time to make another run at the top job, while older men such as Burch, at 58, and Lee, at 61, may view 1978 as their last big chance.

A long standing Annapolis mainstray whose name invariabley crops up in early campaign ruminations is Louis L. Goldstein, Maryland's folksy, "God bless y'all real good" comptroller.

Although he hasn't raised a cent or begun organizing local committees. Goldstein, a shrewd politician, insists on calling himself an unannounced candidate.

His candidacy is not taken seriously by political sources, who say the 64-year-old Calvert County businessman hopes for little more than hitching a "free-ride" on a statewide ticket of his choice and returning for a sixth term as comptroller.

Only Lee and Burch are shooting for treasuries large enough to conduct wide media blitzes. Burch already has raised more than $300,000 toward a goal of $750,000 while Lee has about $125,000 of projected $600,000.

Among the other canndidates, Venetoulis has raised $90,000. Hoyer $70,000 and Orlinsky $35,000. Schaefer supporters have scheduled a $100-a-plate dinner in Baltimore in September. CAPTION: Picture 1, BLAIR LEE III . . . attracts support; Picture 2, FRANCIS B. BURCH . . . top contender; Picture 3, STEPHEN SACHS . . . has raised $122,000