MIAMI -- In late September, Angel Castillo Jr., The Miami Herald's highest-ranking Cuban-American editor, quit and stormed onto a local Spanish-language radio station to vilify his erstwhile employer.

A week later, Castillo, a lawyer and sometime newspaperman, was rehired as outside legal counsel to El Herald, the newspaper's Spanish-language version, whose editor he had been. He now will not comment on why he quit.

So ended one chapter in the continuing saga of The Miami Herald's varied efforts to reverse a long-term downward trend in the number of households it reaches here, even as its prestige has risen.

The decline is partly attributable to the stunning growth in the number of relatively affluent Spanish-speaking residents, mostly of Cuban ancestry. As the newspaper prepares to expand the diminutive El Herald to reach more of that audience, Castillo's highly public departure points up the complex problems of those growth efforts.

The Herald's ties with politically right-wing segments of the community are uneasy. At the same time, younger, more moderate Cuban-Americans complain that the newspaper sometimes panders to an outdated notion that Cuban-Americans are universally obsessed with Fidel Castro and anticommunism.

Younger Cubans in particular sometimes feel patronized by what they see as undue prominence given in the main Herald to what they regard as unimportant stories about Hispanics. "In reading it, you can almost tell they're doing it," Carlos Migoya, 37, a Cuban banker, said.

That view is at odds with the way in which many Herald staffers think of the paper's overall efforts. "To me, The Miami Herald is a newspaper that has won three Pulitzer Prizes in the last two years," said Jim McGee, a Herald reporter who shared in one of the prizes.

Dade County is 43 percent Hispanic, 39 percent Anglo (as English-speaking whites are known) and 18 percent black. Miami has the nation's most affluent Hispanic community and the third largest.

Phil deMontmollin, The Herald's general manager, said the paper recognizes that its continued prosperity requires persuading more Hispanics in Dade to read the Herald -- in Spanish or English.

"Our market is a laboratory of the future," said the Herald's publisher, Richard G. Capen Jr. "There are at least a dozen major cities in the United States that face major changes in their demographics because of immigration."

In 1965, The Herald reached 61 percent of households in Dade County, its home market. By 1985, although Herald circulation in Dade had grown by almost 16 percent, the number of households there had surged by nearly 80 percent. The Herald's share of those households has plummeted to 39 percent.

About 395,000 people have come to South Florida from Cuba since the mid-1960s. Few observers foresaw the growth of an enclave economy here in which many commercial, cultural and social activities can be carried out wholly in Spanish, lessening the pressure felt by exiles in other cities to abandon their native language and learn English.

A recent market study found that 51 percent of the 680,000 Hispanic adults in the area say they do not read English well.

As the Hispanics flowed into Dade, many Anglos fled to other parts of southern Florida. The Herald tried to follow with a spate of zoned editions, but in recent years it has slipped further behind competitors in Broward and Palm Beach counties to the north.

At about the same time, El Herald was launched in 1976. For most of its existence, it has been something of a stepchild. The paper primarily prints translated, shortened articles from the English-language paper. On a recent day when the English-language paper had 82 pages, El Herald had 18.

El Herald's staff is to be enlarged, and there will more original stories in Spanish.

No top Herald editor reads or speaks Spanish well enough to judge El Herald's quality personally or to judge events in the city's Latin community. Some say this lack leaves them subject to manipulation by highly politicized persons who purport to have their fingers on the Latin community's pulse.

In this context, Castillo's reasons for quitting may be less important than public perceptions of what happened.

When Castillo quit, he went directly to a live broadcast by Spanish-language radio station WQBA, accusing Herald editors of censoring an opinion column that the station's strongly anticommunist news editor had written for El Herald.

Some Cuban-Americans here took Castillo's charges as confirmation of what they already believed; others say they were bemused by The Herald's embarrassment.

In the putatively censored column, the broadcaster denied comments attributed to him by a Herald reporter in an earlier story. Top-ranking Herald editors, who believed the reporter, withheld the column because the broadcaster would not change or delete a paragraph they found objectionable. "We do not allow things to go into The Miami Herald that we know to be untrue," Janet Chusmir, the paper's executive editor, said.

The reporter's article said that some Miami radio stations were illegally rebroadcasting programs from Radio Marti, the U.S. propaganda station beamed at Cuba. The broadcaster's quotes in the article seemed to confirm that WQBA and another Spanish-language station had made such rebroadcasts after obtaining the tapes from Radio Marti personnel.

The penalty for such rebroadcasts can be loss of the station's broadcast license, which the broadcaster seemed not to have known.

The next day, Castillo returned from out of town, heard that the broadcaster's column had been killed, told a subordinate to pass on the word that he had quit and headed for the radio station.

"There was a pretty strong reaction," said Miami Mayor Xavier Suarez, who was born in Cuba. "The impression was that The Herald got its foot caught in its mouth."

One key to how The Herald is perceived by older Hispanic readers may be Cuba's different journalistic tradition.

"Journalism in some of our countries at home is not as clear-cut as to what is news and what is opinion," said Carlos Verdecia, a Cuban-born member of The Herald's editorial board. As a result, what is seen by U.S. journalists as presenting a variety of views can be interpreted by some Hispanic readers, especially older ones, as an attack on the view with which they agree.

But 56 percent of the Hispanic adults in southern Florida who read English well are under age 35, and another 30 percent are age 35 to 54. "You don't see the reality I see in The Herald," banker Migoya said. "The Hispanics who are in their mid-40s and above probably spend more time worrying about Castro than people in their mid-30s and younger."

Also, notes Mayor Suarez, "While Cubans tend to be strongly anticommunist, most people are much more progressive on social issues than The Herald seems to recognize."

That makes appealing to Hispanics like traversing a mine field.

One former Herald reporter, a Hispanic, complained that the newspaper covers the Hispanic community "as if it were still a ghetto." But Guy Gugliotta, an Italian-American who covers Latin American news for the paper, says, "the Latin community is the community."

Publisher Capen concedes that the paper "didn't do a very good job" in the past of covering Hispanics here or of hiring enough reporters and editors with the skills and knowledge to do so. But that is changing, he said.

"We need to accelerate the process by putting into place Hispanic editors in decision-making positions," he said. "That is what we were trying to do with Castillo."

By newsroom accounts, Castillo, who also was an assistant managing editor of the main Herald, met resistance from other editors in his efforts to affect Hispanic coverage. Some say his style was abrasive; others that people were naturally reluctant to change a paper they saw as a journalistic success.

One middle-level editor thinks the real reason Castillo quit was that he was tired of the cross-currents of criticism he was getting from Hispanic readers.

"The benefit for The Herald of the Castillo affair," he said, "is that for the first time people here are going to trust their own judgment and just try to cover the news."