The crowd and setting were classic California--tanned and tailored suburbanites, gathered in a blue-and-white circus tent on the plaza of a resort hotel, looking across the tennis courts toward the Pacific sunset. The Republican Associates of Orange County had their white wine and cheese Friday evening and waited for the seven contenders for the GOP Senate nomination to start their forum.

What happened in the next two hours was something else: Friday Night Live in California politics.

The program began with state Sen. John Schmitz, a John Bircher who kicked off his campaign with a joint press conference with Yasser Arafat, saying, "I want to deny the rumors that I have been attending candidates' school in Chile or Argentina."

It ended with the president's daughter, Maureen Reagan, saying, "In the last 22 years, I have helped elect a lot of Republican candidates, most of them disappointing."

In between, the supposed front-runners in the race for the nomination being yielded, semi-voluntarily, by Sen. S.I. Hayakawa (R-Calif.), and their pesky challengers carved on each other in a most un-Republican fashion.

The veteran political operatives on the edges of the crowd assured visiting reporters that the evening's entertainment was totally irrelevant to the real campaign to see who gets to go up against retiring Gov. Edmund G. (Jerry) Brown Jr., the all-but-certain Democratic Senate nominee.

That real campaign is a grim business of begging dollars to buy the TV spots that translate almost mathematically into polling points. Those polls show the past year's front-runner, Rep. Barry M. Goldwater Jr., slipping into a near-deadlock with his closest challenger, San Diego Mayor Pete Wilson, while Rep. Paul N. (Pete) McCloskey Jr., is a rising, but still struggling, third.

The latest poll, taken by Teichner and Associates on May 1 and 2 for KABC-TV in Los Angeles, had Goldwater at 24.4 percent, Wilson at 22.6 percent and McCloskey at 14 percent.

In that real campaign, where the front-runner has been shielded behind his famous name from virtually any contact with the voters, Maureen Reagan is running fifth, with 5.4 percent, behind the three leaders and Rep. Robert K. Dornan, another conservative bomb-thrower.

But if this were not a total media-money state, Friday night's rare live politics suggested that the president might know the ambiguous pleasure of seeing his tart-tongued, independent feminist daughter--who has no real campaign treasury--coming out of the June 8 primary as the challenger to Pat Brown's son, Jerry.

That would be a humdinger, but Friday's warm-up was no bore. Schmitz was up first and left immediately to teach his college political-science class, much to the relief of the others, who find it a little embarrassing to share the platform with a fellow whose anti-Semitic comments have been censured by the state Senate.

Then came McCloskey, the ex-Marine and avowed progressive whose 1972 challenge to Richard Nixon's renomination, on the Vietnam war issue, has stamped him indelibly as a maverick in the eyes of these Orange County Republicans. He leads the pack among the moderate Republicans of his own San Francisco Bay area, and a two-week television blitz in Los Angeles has bought him some support there on the claim that he is (as the polls suggest) the best bet to beat Brown.

Wilson wishes he would disappear and is telling reporters that McCloskey is running out of money. But Friday night, McCloskey was biting on Wilson, criticizing his opposition to the nuclear freeze, and challenging him to say how he would cut the deficits in Reagan's budget. But every word McCloskey uttered put him at odds, not just with Wilson but with Reagan, and he was talking into a wall of icy hostility.

There was a brief pause for a sensible speech by Ted Bruinsma, a law school dean whose standard conservatism is unamplified by television dollars, and then Wilson got his turn.

After killing his opening joke (a skill he has perfected), he resolutely turned his back on McCloskey and said the latest poll confirms it is a two-man race. He challenged Goldwater to a two-man debate, adding, helpfully, "mano a mano."

Wilson was a moderate Republican assemblyman and an effective, almost nonpartisan mayor, a favorite of President Ford, for whom he campaigned against Reagan in 1976. Friday night, as throughout the primary, he was talking a conservative line, stressing his agreement with Reagan on budget and economic issues.

But a questioner wanted to know how conservatives could trust a fellow who not only switched positions but switched races, as Wilson did late last year when polls showed he was heading for the same kind of gubernatorial primary defeat that he suffered in 1978.

He gave an answer that uncomfortably echoed McCloskey's: I can beat Brown.

Dornan followed, as combative as Wilson is bland. He is a movement conservative, backed by direct-mail specialist Richard Viguerie and endorsed by almost all the organizations of the New Right. But California responds to TV, and Dornan has not had the money so far for that--so he is slashing his way to attention.

"Barry, Junior," he said, stressing the "junior," (as all the rivals do, out of resentment at his exploitation of his father's name and influence with contributors and voters), "is a good conservative, but not a leader. He lacks the debating skills needed to beat Jerry Brown."

"Pete Wilson," Dornan said, "is not a conservative. He is a moderate," and even worse, a potential Gypsy Moth, capable of deviating from Reaganism. And it wouldn't be the first time, Dornan reminded them. In 1976, when Wilson and McCloskey were both in New Hampshire, helping Ford gain his narrow victory over Reagan, Wilson had had the nerve to tell reporters Reagan had been merely "adequate" as governor of California.

The buzz of conversation around the bars at the back of the tent died out as Goldwater was called upon. He had arrived late--and many had been guessing he would duck this forum, as he has ducked all invitations to formal debates throughout the campaign. An inconspicuous member of the House for 13 years, Goldwater has become the object of ridicule in this race. Press clips emphasize the efforts to keep his schedule secret from California reporters (although there was no problem in scheduling an interview for The Washington Post), the colorful social life he has led since his divorce, and most of all, his malapropisms.

There are, said one veteran political GOP campaign consultant who watched Friday night, "a lot of Republicans who just think Jerry Brown would eat Barry for lunch."

Asked by a Wilson partisan in the audience about the mayor's debate challenge, Goldwater showed why there is such nervousness about sending him off to face Brown. First, he said, while he has followed the usual front-runner's tactic of declining debates, "there's nothing difficult about debating. I debate every day on the floor of the House and in committee"--a statement his House colleagues considered big news.

Then he said, "We're going to discuss it Wilson's challenge ." And then he added, while his manager winced: "It may be that as Pete Wilson moves ahead, he won't want to debate me."

That set the stage for the First Daughter. A hefty woman, comfortable with her own bulk, accompanied everywhere by one hippy-dressed husband and a platoon of three-piece-suited Secret Servicemen, Maureen Reagan has the same ease on the platform, the same gift for anecdote and the same optimism and charm that made her father such a hit on the banquet circuit.

Off-stage, her comments on her family and her Senate rivals are cutting, but on-stage, she has the best line of patter in the race. She makes both Wilson and Goldwater look like stick figures and ridicules their reverence for the Chief Executive as only a stand-up-to-the-old-man daughter could do.

"Supply-side economics and New Federalism have been Republican policies longer than Ronald Reagan has been a Republican," she said. "I know, 'cause I've been a Republican longer than Ronald Reagan has been a Republican."

All her life, she said, the Republican Party had stood for strong defense and free markets, and all her life it had suffered from the reputation "that we don't care about people."

"I think the time has come for us to take the people issues to the people in 1982 and show them what the next logical steps are to supply-side economics and New Federalism."

In five minutes, she outlined simple, plausible-sounding, Reaganesque programs for youth offenders, for crime-victim reparations, for food co-ops (instead of food stamps) for the poor, for job training and job guarantees instead of welfare.

She sat down to the heartiest applause of the evening and made at least one convert. Dr. Stanford Green said he "could not talk about McCloskey in terms you could quote. Barry Goldwater was more dynamic than I expected but Pete Wilson is clearly superior to him intellectually. But I made up my mind tonight to help Maureen every way I can. There is a sincerity there beyond all the others. She is concerned about values. She was the only one who didn't throw brickbats at anyone else. She was refreshing . . . a sheer delight."

It was the way Orange County Republicans talked in years past about Maureen's father.

But, as the campaign consultant said, "that reaction means nothing. Reagan has told the kitchen cabinet to cut her off at the pockets. She has no TV buy."

And in the real campaign, that means she has no chance against the stick figures.

But for an evening, it was fun.