Hillary Rodham Clinton is under pressure from contributors as well as some New York Democrats to officially declare her Senate candidacy or at least assemble a traditional campaign operation.

Many of these Democrats are frustrated at the loose structure of the "exploratory" campaign, the missteps and the lack of a coherent strategy and message. Rep. Charles B. Rangel (N.Y.), one of the early promoters of Clinton's Senate venture, said last week that he is disengaging from her effort until she officially announces her candidacy.

"There's no campaign manager. There's no issues person. There's no regional person, and if you were to ask me anything at all about what I used to describe as 'my candidate,' I couldn't answer you," Rangel said. "I don't know how to deal with non-candidates involved in campaigns. . . . When there is a candidate, then I will reengage."

That sentiment was echoed by H. Carl McCall, New York state comptroller and a close Clinton adviser: "They have to build a campaign organization and they have to do that touching all parts of the state." But McCall and others say the time for that kind of organization will come--after Clinton has done more traveling in the state and raised more money for a race that already has all the elements of a mega-campaign.

Although Clinton's supporters have been clamoring for her official announcement, Clinton insiders say that she will not do so until at least the end of the year. Her most definitive comment on the subject to date came at a news conference here last week. Asked if it was possible she would not run, she said, "I think that's a remote possibility."

While money is pouring in to reach the campaign's target of $25 million, Sen. Robert G. Torricelli (N.J.), chairman of the Democratic Senatorial Campaign Committee, said donors are eager to see the main attraction begin. "They want to see the fight engaged, but that would be a mistake," he said. "This race is going to be so intense and the debate so sharp that the public can only endure it for a matter of months. . . . So I would simply urge patience."

Torricelli agreed that "the campaign could be more focused on issues and management, but that would come at the cost of spending resources that should not now be spent. I would rather suffer some slight disorganization and make a few mistakes" than spend too much too soon.

Among the mistakes a campaign manager could have avoided, say those close to Clinton's campaign, was the confusion surrounding her position on her husband's offer of clemency to 16 Puerto Rican nationalists. She announced her opposition to the clemency while unaware that the president already had increased the pressure by setting a deadline for the prisoners to respond. And she also announced her position without consulting with the leaders among her New York constituencies who had been lobbying in favor of clemency for years.

"I think it's raised awareness that there is no campaign manager on site in New York state . . . that this campaign's focus needs to shift from Washington to New York, and I think that is happening," said Judith Hope, New York state Democratic Party chairman. "I think of it as a managerial challenge. She has a very lean but capable young staff, and they are doing remarkable work considering how sparse their numbers are."

The Clinton team--including a constellation of advisers as well as a half-dozen paid staff members--has pulled off a series of well-orchestrated "listening events" around the state that have included substantive discussions as well as fluffy photo-ops. These events are aimed at making Clinton more familiar in a state where she has never lived or worked.

"In terms of how the internal organization reaches out, there is no problem whatsoever," said a Democratic source with close ties to the campaign. "In terms of how the outside reaches in, there is this clamoring for a specific contact and structure."

Steve Pigeon, Erie County Democratic chairman, said the campaign needs a "go-to" person--meaning someone who can handle all the questions and needs that increasingly will arise from the party structure. "As she comes here [New York state] more and it becomes more of a campaign mode, you have to have a go-to person."

Harold Ickes, a Clinton loyalist who once was President Clinton's deputy chief of staff, leads the campaign effort, but not exclusively and not full time. He could not be reached for this article, for instance, because he was out of the country for a week with other clients.

Ickes is not slated to become the full-time campaign manager but is consulting with a range of New Yorkers to help Clinton select one. McCall, the Democrat who won the most votes statewide in the last election, is among those advising Ickes. It is time, McCall said, for some clear managerial steps.

"First of all, she hasn't yet been very clear about who's in charge," he said. "I think that's got to be the next step. There's got to be a full-time campaign director."

CAPTION: Hillary Rodham Clinton draws applause at a weekend rally in Albany, N.Y. Insiders say she is unlikely to announce candidacy until year's end or later.