The guest came on the TV talk show between the ads for potato chips and plastic trash bags. He talked authoritatively of the Middle East, critically of federal spending boastingly of U.S. intelligence agencies and optimistically of Republican chances this fall.

Then, as hundreds of thousands of viewers in six cities watched, he was asked whether he is running for president.

Moments later, after a luncheon speech. George H. W. Bush would again be asked if he is running for president. And then in a series of press conferences in a string of cities, Live Eye News. Eyewitness News, Action News, Scene 17 News, 21 Alive News and The News would also wonder if George Bush is running for president.

It seems that almost everyone wants to know whether George Bush is seeking the presidency.

"Who's George Bush?" asks a woman standing six feet from him at a Fort Wayne fund-raiser for Republican Rep. Dan Quayle.

He is, of course, the former Texas congressman, the former ambassador to the United Nations, the former Republican National chairman, the former head of the U.S. mission to China, the former director of the Central Intelligence Agency.

"Oh, that Bush." she said.

It's your basic name-recognition problem." Bush himself wistfully laments after being asked in Michigan what office he is interested in.

Such is the unannounced candidacy of George Bush, a Texan who has been elected to only one office - representing a rich white Houston district in the House. An improbable candidacy, you might say.

Improbable, except for what Democratic National Chairman John C. White calls a "revolutionary change in politics," brought on by the growing number of primary elections. There will be close to 40 in 1980.

To win the presidential nomination, says White, "It used to be you had to have a tremendous national constituency. Now you can build one as you go along, particularly if you can knock off a couple other candidates.

"You build your momentum or you lose. Momentum is everything."

Republican National Chairman Bill Brock added. "The primaries now have so much more to do with the nominating process." He said 1980 now appears to offer the first wideopen Republican contest, presenting a large number of candidates in the Age of the Primary.

And one of them will almost certainly be Bush. "The Bush people," says one intimate, "I foresee 1980 as a mirror experience for the Republicans of 1976 for the Democrats: Throw all you've got into the early primaries and hope you finish first, and build from there.

"Develop the momentum and hope that by the spring of '80, a good number of others will have dropped out."

"Someone," says Bush himself, "is going to have to get discouraged somewhere along the line." He adds, too, that if he runs, he will have to enter "all or almost all" of the primaries.

Having solid party appeal from his days as national chairman, Bush now must demonstrate a more popular appeal.

Crucial, of course, to the strategy is an erosion of support for the current odds-on favorite for the Republican nomination. Ronald Reagan. "Right now, Reagan's the frontrunner," said Bush. "In my view, what today appears to be a formidable obstacle might or might not be the formidable obstacle in 1980. A year is an eternity in politics; lots of things can happen."

Like other Republicans, Bush sees Reagan's strength now as a possible weakness later. In recent history, no frontrunner at the midterm elections has gone on to win the nomination.

For the record, George Herbert Walker Bush, 54 and a Texas millionaire, is not now a candidate.For the record, he is "leaning that way" and is "seriously interested." And for the record, he said recently while flying over the flat farmlands of Indiana, if he decides to become a candidate he will announce early next year.

"I just think," Bush said, "the fall of 1978 is too damned early to be announcing as a candidate. It's not too early to be doing some of the things that someone who is not a basic household word has to do."

So meantime he is, in his words, "constructively unemployed," serving on the boards of directors of several corporations and crisscrossing the United States - 32 so far - making appearances on behalf of Republican candidates.

Bush's travels are financed by his political action committee, the Fund for Limited Government, in Houston. The fund is headed by James A. Baker III, who was national election campaign chairman in 1976 for then President Gerald Ford. It has raised about $100,000 so far, with sizable contributions from oil executives and others active in investments.

"If George Bush gets the nomination," says a close associate, Texas legislator Chase Untermeyer, "it will not be because of China, the U.N. or the CIA. It will be because he was national chairman during Watergate."

At that time, Bush was in daily contact with the party activists who influence Republican nominations far beyond their numbers. In eight months and 150,000 miles of travel, he built their spirits, spoke at their Lincoln Day dinners and dissociated the party from the crimes of Richard Nixon's hirelings.

"He did it with grace and dignity," all Texas couldn't save me."

On the tarmac of the Fort Wayne airport the other day. Bush openly declared. "I'm going to run."

But before anyone could read significance into that, he reached for the blue denim sack containing his jogging clothes. "Yes," he said, looking out over the flat tracts of Indiana from his hotel room windows, "this looks like a good place for running."

The calendar favors George Bush in one respect - the primary election in his home state of Texas comes relatively late, the first part of May. Yet Reagan's support there is superstrong, almost spiritual, presenting difficulties to both Bush and former governor John B. Connally.

"If I won a lot of earlier states over Reagan I would do better against him in Texas," Bush says. "If I lost them says John McDonald, Iowa's national committeeman.

Bush sees himself as a candidate who can bring the party together; Ford-Reagan battles divided it in 1976. When Ford was selecting a vice president in 1974 after Nixon's resignation, Bush was the second choice of many Republicans whose favorites were Barry Goldwater on Nelson Rockefeller (the New Yorker was chosen).