Charlotte and Bob Wilder are expecting 60 neighbors to drop by their green and white ranch house on West Third Street Monday to start the 1980 presidential election process.

Charlotte Wilder, who has been the Warren County clerk for the last 15 years, will recognize almost everyone's face, and she expects most of them to be supporters of President Carter, who has spent more than a little time in this town of 12,000, which was once known as "The Holy City" for its 18 churches.

If more people come, Sen. Edward M. Kennedy (D-Mass.), Carter's arch-rival, will do better than Wilder expects. "We could handle 75 people at our place, but I think I might have to clean the basement," she said Tuesday.

The presidential campaign has been going on here for months, pitting neighbor against neighbor, friend against friend. "It's been fantastic. We've really capitalized on it," Steve Hoover said in an insurance office. "My wife and I have seen every candidate. We've personally met every Republican, except John Anderson."

Hoover has become the Warren County Reagan-for-President chairman. His wife, Jerri, running for county GOP chairman, is undecided. "She's leaning toward [Ronald] Reagan or Bob Dole," her husband said. "The Doles have really been terrific to us. They sent us a Christmas card and called us on the phone. We went up to Des Moines last Saturday to meet him, and when his wife came here last week Jerri took her around. Dole remembers our name. That's a pretty big thing when you come from a little town in Iowa."

Such is the stuff of presidential politics in this state, whose Jan. 21 precinct caucuses will provide the first test of the 1980 presidential race.

There's a highly personal type of politics, unfamiliar to most Americans, who have grown accustomed to politics-by-media. It is fought and decided in seemingly insignificant one-on-one battles.

The caucuses are being treated by the media as the equivalent of a primary election, but they aren't.

The rules of participation are loose, and the caucuses are small, intraparty affairs that traditionally attract only a cadre of Republicans and Democrats. a

In 1976, for example, 58,000 of Iowa's 1.5 million registered voters took part, compared with 200,000 people who voted in the New Hampshire primaries a month later. In precinct No. 3 in Indianola, where the Hoover and Wilder families live, 55 of the 396 registered Democrats and 14 of the 440 registered Republicans showed up for the caucuses on what everyone remembers as a bitterly cold January evening.

The caucuses are in effect a series of backroom party meetings, held in homes, schools and churches in each of Iowa's 2,351 precincts. The chief business is selecting delegates to county party conventions, where delgates are selected in turn to district and then state and national party conventions, a process that will stretch out until summer.

The trick for each candidate is to get as many of his supporters as possible to each precinct at 8 p.m. next Monday. Anyone who can bring along an extra dozen or so people becomes a power broker of sorts.

In 1976, Carter, then an obscure former governor of Georgia, captured seven of the delegates elected in the caucus held in the Wilders' crowded living room. Fred Harris, a former Oklahoma senator, had two delegates. Five were elected as uncommitted. At the Republican caucus nearby, the crowd was a Reagan one.

A look at Indianola four year later gives an intriguing glimpse at the crucial opening stages of the 1980 presidential race and its possible outcome. For entirely different reasons, the two most interesting campaigns here are those of Carter and George Bush, the former U.N. ambassador and CIA director.

"A year ago there were very few people who would sit in this chair and admit they voted for Jimmy Carter," Donald Heavilin said in Don's Barber Shop on the Courthouse Square. "There's been a lot of zigzagging going on since then. Kennedy has gone up and he's gone down. I don't think I've ever seen so much shifting of attitudes."

Carter developed a hard-core following of supporters in Indianola, an agriculture and bedroom community about 15 miles south of Des Moines, during his 1976 campaign. They say they feel the president has not forgotten them.

One night last year. Carter spent a night at the farm house of W. W. (Woodie) Diehl, one longtime supporter. Chip and Jack Carter, the president's sons, have both visited here in recent months. So have Rosalynn and Lillian Carter. And last October, the president invited the Wilders, the Diehls and state Rep. Phil Davitt and a group of other Iowans to the White House for a day-long set of briefings and ego massage.

Now Carter is the odds-on favorite here.

Kennedy visited Indianola one afternoon last week, attracting about 450 supporters to a rally at Crouse Cafe. Two days later, 275 turned out to hear Bush at a breakfast rally at the First Methodist Church. Sen. Bob Dole's wife, Elizabeth, Sen. Howard H. Baker Jr's daughter, Cissy, Ronald Reagan's Son, Michael, and John B. Connally's son, Mark have also been here in recent days.

But the real battle here is a largely invisible one, waged on telephones and in conversations between friends.

Loren Gruber, an English professor at Simpson College, is heading the county Bush effort. He let Bush headquarters in Des Moines know he was interested in helping out after he received some Bush literature in the mail in July.

"Bush was the first candidate to mail me information. I read it and liked what I saw," he said. In late September, he learned that his boss, English department chairman Donald Coch, had become the local Connally chairman. "I called Des Moines in a panic to ask them who was our chairman," he said. "I ended up with the job."

Since that time, Gruber has become a true believer. Much of it is the result of Bush's personal touch. Gruber has written him four letters, asking his stands on various issues. Bush replied to all four, several times with hand-written notes.

Reagan has been hurt by his failure to campaign more in Iowa, and his refusal to join six GOP rivals in a Jan. t7 nationally televised debate in Des Moines.

"I guess the race is going to be between Bush and Connally here," said Lewis Kimmer, publisher of The Record Herald and Indianola Tribune. "I just don't think he can cut it in Indianola anymore."

A straw poll is to be taken of all people attending Republican caucuses across Iowa. This vote is to be reported to the state party, and is to become the measurement used to calculate how candidates fared in the caucuses. The figure is not too meaningful, however, for delegates will be selected separately.

The Democratic caucuses will provide a better account of the strengths of the candidates. At them, voters will divide themselves into groups. Those supporting Carter will gather in one part of the room, those for Kennedy, California Gov. Edmund G. (Jerry) Brown Jr., or uncommitted, will gather elsewhere in the room. Each precinct's delegates to the county convention then will be apportioned according to the number of supporters present.

"Elections are always crazy. But this one is really crazy, because no one will know who's going to show up until Monday night," says Alan Slomowitz, a Kennedy field worker from Washington assigned to this county.