The American public is about to witness a spectacle of symbiosis between politicians and the press -- a chicken-and-egg game surrounding Saturday's Democratic caucuses in Florida.

The press is here in vast numbers because the politicians are here. The politicians are here because the press is. Many headlines and much TV news will follow, concerning who "won" and who "lost" in these caucuses, the first in the nation. But not a single delegate will be chosen.

The charge of "media event" has been flung at the early machinations of presidential campaigns -- particularly the New Hampshire primary -- for some time. But the Florida caucuses have elevated the media event to a whole new level. They are five months earlier than New Hampshire. And unlike the New Hampshire primary, this is merely an expression of party sentiment. In terms of the 1980 nominating conventions, nothing will happen there.

This story is in the nature of a warning to consumers of the news, an attempt to explian how the Florida caucuses became such a big deal.

"The first time I realized something was peculiar was when one of the TV stations called me and asked about who was renting my buses," says Elliott Hecker, the sales manager of American Signtseeing Tours here and until this month a man convinced that he had seen it all in the transportation business.

Hecker shrugs his shoulders in bewilderment. "Then some other people in the media called. I thought somebody was putting me on. I've handled three national political conventions. Nobody fought for buses. The Super Bowl wasn't this bad. What are they making such a big deal out of this for?"

Just about everybody affected by Saturday's Democratic caucuses here -- from political organizers to reporters to unsuspecting bus company executives like Hecker -- feels that the fuss being made over these caucuses is completely out of proportion to their importance. Early presidential campaign politics seems to have taken on its own momentum here, illogical but nonetheless irresistible.

Florida voters won't actually choose delegates to the national conventions until March 11, but over the next month, the public will be exposed to a series of psychological struggles among candidates that will set the early tone for the 1980 campaigns.

Left to their own devices, the Democrats of Dade County would probably stay away from their caucus in droves. But the two campaign don't intend to leave them to their own devices, and the media won't let anyone alone.

Here and in other populous Florida counties, wire service reporters will interview every single voter emerging from the caucuses. The reason is that official rsults may not be ready until next week and the newspapers are eager to print the results in Sunday's editions.

The television networks, the news magazines, The Washington Post and The New York Times each will have at least two reporters in Florida on Saturday. It's safe to say that on one connected with the caucuses in any way will be denied the pleasure of direct contact with the working press.

Members of the press insist that it's the politicians who turned the caucuses into a major event. They say President Carter's heavy campaign efforts here and Sen. Edward M. Kennedy's tacit approval of the people working on his behalf are what make the caucuses an important story. "It's not us who are making a big deal out of it," says Henry W. Hubbard, Newsweek's deputy Washington bureau chief. "It's the candidates."

The politicians disagree. "The press was heavily involved before I was," says Jay Hakes, Carter's chief Florida organizer. "We're just responding to a heavily published challenge. Before this I worked at the Interior Department, and I got one call from the press the whole time. But when I got down here, the phone rang off the hood. Lots of reporters like to cover presidential elections and they don't have much to do right now."

The truth is somewhere in between and require a little hisorical explanation.

Among policical reporters and politicians and their technicians it is generally agreed that The Times and The Post set the agenda for the press' coverage of national politics. Four years ago in the fall of 1975 the two papers took divergent courses in their handling of the earliest stories of the Democratic campaign.

The Post's chief political reporter David S. Broder decided in 1975 that he would ignore early caucuses and straw votes that did not involve the actual selection of delegates to the Democratic Nation Convention. Broder was heavily influenced by the work of Duke University political scientist James David Barber, who stresses the importance of the president's character as revealed by studying his early life, to understanding his conduct in office. Broder and The Post's political team spent the fall of 1975 writing in-depth stories about the records, positions and reputations of the various candidates.

But Broder's then opposite number at the Times, R.W. Apple Jr., took a different course. In October 1975 he wrote a lengthy article based on Jimmy Carter's first-place finish in a straw poll of 1094 people at a political dinner in Ames, Iowa. A month later Carter won the Florida convention straw vote and Apple wrote a fron page report about it the next day calling it "a significant show of strength." The Post barely noted the Florida straw poll.

If Carter hadn't won the 1976 monination, this year's Florida caucuses and straw roll might not be so heavily covered. Because he did win, it became the lore of the press that no straw vote no matter how small its real significance should be ignored. And because of the chicken-and-egg nature of these matters, that means that early tests like Florida's are highly important to the candidates because the press will be covering them so heavily. i

Another reason the Florida caucuses have become such a major event has to do with ambition and infighting in the Democratic Party here.

In 1975, the chairman of the Democratic Executive Committee of Florida, Ann Cramer, decided that the party should hold a convention and straw poll in order to lift the spirits of party activists, attract national attention to Florida, and make money. "We wanted to promote the idea that Florida is a microcosm of the nation," says the party's executive director, Greg Farmer. "We saw the convention as a way that the party could influence national politics."

The convention did indeed draw attention and make money. Shortly after it was over, Cramer was unseated as party chairman by Alfredo Duran, a Miami lawyer who represented a coalition of young South Florida liberals.

Two important members of that coalition, Mike Abrams and Sergio Bendixen, were, like Duran, strong Carter supporters at the time. Abrams ran the 1976 Carter campaign in Dade County.

But when Carter took office, Abrams and Bendixen became disaffected. They were disturbed by what they saw as Carter's drift toward political conservativism, and by his personal inattention to them. Specifically, they were miffed when the White House party for Floridians held last year.

Early this year, Abrams and Bendixen spoke with an aide to California Gov. Edmund G. (Jerry) Brown Jr. about the possibility of Brown's coming here, but nothing came of it. Then they set up the Florida for Kennedy Committee.

In April, the state Democratic Executive Committee met to decide whether to hold a presidential straw poll at this year's party convention.Only one member of the committe, Ann Cramer, voted against it, on the grounds that the poll could prove embarrassing to Carter.

The Kennedy forces supported the poll because, as Bendixen puts it, "we thought it ould be a good vehicle for us." The Carter forces supported it because, says one member of the executive committee, "it's absolutely good for the party to get media."

Well, the party has certainly got media. But what the media has gotten won't be clear until the circus is over Saturday and what passes for results are in.

That's when the most delicate question about the etiquette of media events will arise: how to write about them. If the caucuses are important because of perceptions, what outcome will constitute a perceived Carter or Kennedy win?

It's a delicate question because there's considerable disagreement over its proper answer.

"I have a sense that Carter's favored," says Robert Ajemian, the Washington bureau chief of Time magazine. "What number he has to get for it to be a victory, I don't know." If that's the case, reporters and editors will have to decide on Sunday how big a Kennedy vote constitutes a strong showing.

On the other hand, there's the view that whoever gets a simple majority will be the winner. "You could always say Kennedy made a strong showing, but I don't buy that," says William Kovach, Washington editor of The Times. "It's a win-or-lose situation."

Or it could be that with Kennedy far ahead in the national public opinion polls, even a strong showing by Carter will be big news. "If Kennedy loses it'll have a very large, major impact," says James Doyle, Newsweek's chief political writer, "because right now Kennedy is perceived as the front-runner."

Whoever is right, by now so many people have invested so much time and money in the idea that the caucuses are important that it's inconceivable that the results will be soft-pedaled. So on Sunday morning, on the basis of a strange amalgam of delegate counts from some counties and wire service polls from others, the people of America will learn which man is ahead in a contest in which no real votes have yet been cast.