Worried that any misstep would cost them heavy political damage, the leaders of the Democratic Party have chosen a course of conscious invisibility for the time being, while searching for clues to the path back to power.

Under their new chairman, Paul G. Kirk Jr., the state chairmen and members of the Democratic National Committee went through three days of meetings this week in which they never raised their voices and rarely opened their eyelids.

"This body is morally, spiritually and intellectually dead," veteran DNC member Richard M. Koster said yesterday. "It's just lying here like a piece of hamburger on the griddle."

That's an overstatement, but the most striking aspect of the session was the deliberate effort by almost everyone to obey Kirk's command to lower the decibel level on such perennial points of dispute as party rules, policy statements and the status of rival constituency caucus groups.

For the 1985 Democrats, opening their sessions with prayers and patriotic songs, the motto seems to be "Bland Is Beautiful."

After watching Kirk gavel through a move to abolish the scheduled 1986 midterm convention over the objections of some liberal activists, former party chairman John C. White, who was at the helm in the troubled period from 1978 to 1981, said, "If I had tried to do that, we'd have had armed guards in here."

White, a Texas moderate allied with former president Jimmy Carter, said that Kirk, a former aide to Sen. Edward M. Kennedy (D-Mass.), "could do what I couldn't because he's got the credentials" with the liberals.

Since Kirk's hard-fought election in January, he has moved methodically to alter the party's image as the willing agent of its activist constituencies.

In addition to killing the "mini-conventions," he has:

* Stripped a variety of demographic and ideological groups of their status as officially designated Democratic Party caucuses.

* Denied the black caucus' authority to designate its own choice as party vice chairman.

* Denounced organized labor's tactic of endorsing a presidential candidate before the primaries begin.

* Defied pressure from women's groups for half the seats on a new party policy council -- thus breaching the "equal division" rule for which they had battled.

Some of the changes are more cosmetic than real. The caucuses still meet, and Kirk's 25 appointees as at-large members of the DNC included 15 union representatives, 13 women and nine blacks -- at least as many as each of those groups had had previously.

But Kirk has sent significant signals to the South and the West -- where disaffection from the national ticket was sharpest in 1984 -- that their help is needed.

He has named white males from Dixie and the Mountain West to head two important party commissions: Donald L. Fowler of South Carolina to reexamine nominating rules and former Utah governor Scott Matheson to devise a policy statement for the midterm campaign.

Both panels are under orders from Kirk to work fast, keep controversy to a minimum and close up shop -- the rules-makers by the end of the year, the policy-makers by next spring.

The Fowler panel held its organizational session yesterday and agreed to hold four regional hearings in August and three or four meetings in Washington between September and December to write its report.

Kirk told the commission, "We have to be interested in affirmative action . . . but the only quota I'm interested in is 51 percent of the electoral college" in 1988.

For the most part, DNC members applauded Kirk's bottom-line, no-nonsense approach, even while some said privately that it made the atmosphere "more Republican than Democratic."

"I think it's important for the political insiders to know that this party is focused again on winning elections," said Tennessee chairman Richard Lodge. But Lodge said the general public has yet to hear any message from the Democrats that will win back support lost to the Republicans in recent years.

While Kirk said that "we have to step back from our own agenda and unite around a broader vision," he and his lieutenants virtually concede that, except for applying a degree of discipline -- a favorite Kirk word -- to the party's internal feuding, the search for that "broader vision" is just beginning.

Brian Lunde, Kirk's executive director, said the DNC will invest a half-million dollars in a series of focus group interviews and a massive, 6,000-person voter poll, seeking themes Democrats can use to regain support. Lunde said the study will be run by Phillip Kotler, a marketing expert at Northwestern University, because "we're not even making the assumption that we know what questions to ask any more."

The makeup of the Matheson policy commission -- more that two-thirds of the elected officials are from state and local government -- reflects another effort to look beyond the usual sources for guidance on the future party direction. Matheson conceded in an interview that he is not sure what national policy ideas those city, county and state officials will recommend -- or how specific they can afford to be on issues like trade and taxes, which cut across regional and interest-group lines.

"Everyone says the Democrats have to be receptive to the issue of economic growth," Matheson said, but that new party catch phrase has as many interpretations as there are Democrats.

Several DNC members suggested that tax overhaul may turn into a good issue for Democrats, if they can spread the notion that President Reagan's proposal would benefit mainly wealthy taxpayers and increase deficits.

But in the prevailing atmosphere of caution, the DNC appeared nervous about touching even that issue. A proposed resolution endorsing the Bradley-Gephardt bill, the leading Democratic alternative to the Reagan tax plan, was submerged into a broad commendation of Democratic leadership on the issue, when Kirk indicated to its sponsor that labor might have reservations about the specific reference.