The fund-raising letter describes New York's 1980 Senate election as a "a constantly changing scene" and then makes its pitch: "A group of us have decided that John Lindsay is our candidate."

John Lindsay? In 1980?

Lindsay's effort to relaunch a political career that crashed in more places than Skylab is only one aspect of a Senate campaign that promises to keep New York's political waters boiling.

The state doesn't have a 1980 presidential candidate to watch through the early paces of a long-distance run, but long before the election a large field is off and running for the Senate seat held by Republican Jacob K. Javits for 22 years.

Every one of them is an undeclared candidate. Even Javits is keeping everyone guessing whether he will run again next year, when he will be 76.

The Senator has said that he will decide in February. "My criteria will be how I feel, the state of my state and the state of the nation," he explains.

While Javits waits, former Miss America Bess Myerson, Rep. Elizabeth Holtzman, Manhattan Borough President Andrew Stein and New York Secretary of State Basil Paterson are busy testing the waters on the Democratic side.

President Carter added a new twist to the campaign when he fired Health Education and Welfare Secretary Joseph A. Califano Jr. Brooklyn-born Califano denied any interest in making the race earlier this year, but now he says he doesn't know what his future plans are.

Lindsay and Holtzman have been working hardest to raise money and solitic political support around the state, but Myerson and Stein come to the race with enormous advantages.

Myerson is well-known and well-liked, according to all polls of New York City voters. She has a drawer full of IOUS from politicians she has helped in earlier campaigns.

Myerson played a vital role in Mayor Ed Koch's 1977 campaign and Kock says openly that he thinks she will run and he will support her if she does.

Sen. Daniel P. Moynihan also benefited from the Myerson touch in his primary campaign against former representative Bella Abzug and he's grateful. Moynihan has said that she would make a fine senator despite her lack of political experience and has been telling friends that he will help her. Gov. Hugh Carey is more cautious, but he likes Myerson and will undoubtedly be with her if she makes an energetic race.

Myerson, who has never run for office, has acquired a reputation as the woman who won't say yes. Again and again New York politicians have urged her to enter a campaign without success.

Myerson, 54, says this year is different. She has engaged Peter Hart to take an in-depth poll and she has been talking with lots of people about running.

"I have always been put up at the starting gate by someone else. Every time there's a race, someone puts my name in a poll, but this is the first time that I've done the work required to make a decision," she said.

Stein's reputation is that he can't say no. At 34, Stein has been running hard and throwing elbows into anyone in his path for years and although he has made a lot of enemies, he hasn't lost an election.

"I don't think Myerson deserves to be a senator," Stein said. "She wants to run and win without muddying herself. Her idea of campaigning is to hang out with the big-shots."

The message is that if you run against Stein, you get muddy. Ask anyone who has run against him.

Last year, Stein didn't have anything to run for himself, but an old foe, Stanley Steingut, the state Assembly speaker, was up for reelection. Stein was instrumental in beating Steingut in the primary.

He has become the outsider of Democratic politics. Hardly a week goes by without a Stein jab at the mayor. He has attacked Manhattan's West Side Democratic reformers as "hypocrites." He was the first New York officeholder to come out for Sen. Edward M. Kennedy (D-Mass.) for president in 1980.

Stein is not bashful about his biggest asset, his money. Stein's spending will probably make the 1980 race far more expensive than earlier ones. Moynihan won a primary and general election for about $950,000 in 1976, and Stein speaks of spending more than that for the primary alone. A lot of it will be his own money. His father, Jerry Finkelstein, is the publisher of the New York Law Journal.

While Myerson and Stein have been consulting in New York City, Holtzman and Lindsay have been on the political circuit in upstate New York.

"I've been very encouraged by the responses," said Holtzman, 37, who was elected to Congress after she defeated Emanuel Celler in a startling Democratic primary seven years ago.

People are saying now, as they did then, that she isn't well enough known to raise the money and get the votes to win. "It's true Celler was well-known, but he wasn't well liked," Holtzman remarked. She thinks she can pull another upset and she is the only candidate with Washington experience other than Lindsay.

In an effort to demonstrate that she can raise money and also because she is a strong supporter of financial disclosure, Holtzman, although she didn't have to, filed a report showing she raised $97,311 since June 30.

"I don't want to give up my seat in Congress lightly. I want to be sure there's a good chance of winning," Holtzman said.

In an age of instant politicians who gained celebrity in another line of work, a Holtzman victory would be a win for a serious politician who doesn't shine on television.

Remember Fun City? That's what New York was called when it had a glamorous mayor named Lindsay who seemed destined for even higher office, maybe the White House.

The fun stopped abruptly. A New York Times/CBS poll of registered Democrats last year found that more blamed Lindsay for the city's fiscal crisis than pointed their fingers at his successor, Mayor Abraham Beame, or the banks or municipal unions.

Lindsay, 57, must erase a lot of voters' memories to have a chance. He refused to discuss his Senate ambitions, and referred questions to a spokesman for the organization formed to boost his campaign -- The 1980 Committee. "People have been generally sympathetic," the spokesman said.

Lindsay would count heavily on black and Hispanic voters in the city and upstate voters if he becomes a declared candidate. His fragile strategy would become even more difficult to execute if Basil Paterson, a black, enters the race.

Paterson is well-liked and respected by politicians but little known and without campaign resources. He has said he will run if he can raise enough money, but he would be a longshot.

While the Democrats scramble, the Republicans are waiting for Javits to make up his mind. Rep. Jack Kemp is eager to run and might even take Javits on in a primary. If Javits steps aside, Kemp, the co-author of the KempRoth tax cut bill and former pro football quarterback, could emerge with the nominations of three parties.

The Right to Life Party polled 130,000 votes in 1978 and has become a force in the state. Kemp, a strong opponent of abortion, would be their likely choice and he is a favorite of the Conservatives.

In the wings stands Henry A. Kissinger. He has never minded seeing his name mentioned as a possible Senate candidate, but as the election draws nearer, it seems less likely that he would want to join in the political fray.