Mayor Frank F. Fasi faces the most exciting prospects of any local government official in the United States. By next year at this time he figures to be either in the governor's mansion or on his way to prison.

Fasi's expectations, which are seen in similar terms by both friends and enemies, arise from a combination of his own persistent popularity and of his ongoing trial for bribery arising from contributions made to his political campaigns by developer Hal J. Hansen.

"Ongoing" may be stretching it a bit. After a year of investigation and state expenditures believed to exveed $400,000, the attorneys in the case have yet to make opening arguments, Fasi himself claims to have spent more than $200,000 in his won defense some of it for a far-reaching and effective public relations campaign which describes him as the victim of a political vendetta launched by Gov George R. Ariyoshi and his appointed attorney general, Ronald Y. Amemiya.

If cendetta it is, there appear to be few in Hawaii who think it is an effective one. Last week, out of sight of thejury, star witness Hansen was alleging under oath that his testimony had been coered by fear of prosecution. Meanwhile, even Ariyoshi's own private polls showed Fasi with a substantial lead in the 1973 Democratic gubernatorial primary, an event that usually is tantamount to election in Hawaii.

Fasi, in fact, is seen as nearly sure winner if he beats the bribery charge, and there are some who say that he could emulate the feat of legendayr Massachusetts politician James Michael Curley and win the race even if he was convicted. That wouldn't be possible, however, since Hawaii law removes a felon from office upon conviction and bars him from running for any other post.

Nevertheless, there is a kind of "last hurrah" Curley flavor to Fasi's style of politics, although the 57-year-old mayor in physical appearance more nearly resemble Massachusetts ex-Gov. John Volpe.

Los Angeles Times sports writer Jim Murray, a classmate of Fasi's at Conneeticut's Trinity College, once wrote that "we always knew 'Fazz' was going somehwere - either the White House or the big house."

Murray said that Fasi, who is color-blind used three separate russes to get into the Marine Corps in World War II first memorizing the color charts, the hiring a double to take the test and finally switching test records when the media wasn't looking. The Marines, admiring his persistance, let him in.

Fasi, the son of a still-living Sicilian immigrant who became a Hartford Conn. icemen, first came to Hawaii as Marine, and it looked good to him after the war when he returned home to a snowstorm. He borrowed $400 from a younger sister and came back to Honolulu where he capitalized on the lack of building materials here by launching a salvage business that, among other things toe down his old Marine barracks. The business made Fasi a millionaire.

"When Lady Luck came knocking on my door, I didn't just let her in, I went to bed with pride on a career that include two wives, 11 children, three political offices and a thousand controversies.

As mayor of the City and County of Honolulu, a jurisdiction of 608 square miles, which includes the entire island of Oahu and a population greater than San Francisco or Boston, Fasi seems a throwback to an earlier, flashier Easter style of politician who was often accused but seldom found guilty.

His feisty, combative style combines with a frequent exploitation of populist issues to win voter approval. Through he has valuable land holdings, Fasi won offic in 1963 by campaigning against the "developer-oreinted government" of the previous administration.

He has won re-election twice, by a record margin in 1976, on the strength of such issues as a 25-cent subsidized bus fare that Fasi would make a free fare if the legislature would let him.

He organized a fund to have the city's gymphony and sold tickets personally to help keep the Hawaiian professional baseball franchise alive.

"Fasi's an upperdog who has successfully portrayed himself as an underdog" says Hobert Duncan. Ariyoshi's press secretary and the managing editor of the Honolulu Star Bulletin until 1976. "He manipulates the newspapers very effectively, as he did when I was there, ia guess I admire him for that. He always had a dragon to slay and a evil to remedy."

Fasi also has mastered the use of television. On the eve of his trial, he bought a half hour of television time to portray his side of the case, calling the program, "My Side of the Story."

The mayor readily acknowledges that he raises campaign funds from the contractors developers and professional people who do business with the city but says he has never taken a bribe.

"I'd throw any of them out of my office on their as if they even mentioned a bribe," Fais says.

Fasi also acknowledges that the Hawaiian political system, which has few legal restrictions on campaign contributions, invites corruption, an admission which the prosecution sees as an attempt to establish an "everybody's doing it" defense.

"I get my campaign funds from the same source as any other officeholder - from the people who do business with the government," Fasi says. "It's a rotten system that outht to be changed."

The case against Fasi is that he and his former campaign treasurer and co-defendant Harry C. C. Chung agreed with developer Hansen to accept a $500,000 bribe in the form of campaign contributions in returen for the right to build a $50 million highrise residential development known as Kugui Plaza.

Only an estimated $80,000 of the money was ever paid, and the cse against Fasi himself admittedly is circumstantial. The prosecution hopes to show that Chung was acting as Fasi's agent in conspiring with Hansen to accept the contributions.

Ever since his indictment by a grand jury, Fasi has been trying to put the Arlyoshi administration and the prosecution on trial in the public arena. By last week he appeared to have succeeded, aided by a $25 million lawsuit brought against the prosecution by Hansen, who claimed "to talitarian tactics" were used to force him to testfy.

The chief target of the lawsuits is California trial lawyer Grant B Cooper, better known for his publicity attracting defense role in the Sirhan Sirhan and Dr. R. Bernard Finch cases. Cooper, now 74, was named special prosecutor by Ariyoshi on the recommendation of Attorney General Amemiya, who says Cooper was recommended to him by former Watergate special prosecutor Leon Jaworski.

Cooper already has collected more than $200,000 from the state for his year's work, based on a rate of $570 a day when he is in court and $500 for all other days.

No one doubts Cooper's trial skills, but the move has backfired politically. Fasi persistently calls Cooper "the hired gun" from the mainland and last week accused the prosecutor of "knowingly and wilfully" lying to federal authorities when he sid in a letter that Fasi and Hansen had met together to disucss the purported bribe.

It is no accident that the words "knowingly and willfully" wee the same as those used by the California Supreme Court when it fined and reprimanded Cooper for lying about the source of grand jury documents in a 1971 case.

Prosecutor Cooper shrugged off the Fasi allegations and maintained that Hansen will be a forced and effective witness when he eventually tesities in the trial. He says that the developer, who has been granted state immunity, is trying to play "both sides agianst the middle" because he faces a cariety of federal charges for which Cooper can not grant him immunity.

However, Fasi seemed ebulliently confident as he hammered away recently at Cooper and at Ariyoshi, who has acquired a reputation as an indecisive and somewhat inarticulate political figure.

The island newspapers interrupted their long-standing feud with the mayor long enought to criticize the governor sharply for refusing to protest the threatened execution of Philippines dictator Ferdinand Marcos. Fasi protested the execution sentence in a strongly worded telegram designed to appeal to Hawaii's Filipino population, while Ariyoshi went off quietly on a previously scheduled tour of the Philippines.

Small wonder that Fasi appears confident of defeating the governor if he is acquitted of the bribery charge.

Last week, in an office decorated with pictures of John F. Kennedy and Pope Paul VI, Fasi held court for visiting reporters. He spoke softly puffed slowly on a pipe and fingered a medallion given him by a Teamster official which is a St. Christopher medal on one side and the Star of David on the other.

"I can't lose with this," Fasi said with a broad smile, "and I'm not going to lose, I'm going to make it. You're talking to the next governor of Hawaii."