Few in southern California's vast community of immigrants, past and present, can remember the name of the last western regional INS commissioner. (It was Edward O'Connor.)

Harold Ezell, his successor at the Immigration and Naturalization Service, is quite another matter.

Ezell, 49, has appeared on every television station (and many radio stations) in every major market in southern California. He has virtually dragged local politicians and reporters along on his regular trips to the Mexican border. He has helped direct an Arizona investigation of immigrant smuggling that has set church and state on a collision course.

He has even persuaded the Los Angeles City Council, a body that does not often defer to the edicts of mere federal officials, to change its position.

In the process, the stocky, curly-haired former hot-dog chain executive has not only become the most recognizable federal appointee in the West but has touched a raw nerve here. It remains to be seen if the millions here who still enjoy a booming economy partly fueled by Mexican immigrants can be roused to do much about the porous border, but Ezell's energetic, multi-media prophecies of immigrant gridlock have had an impact.

"He single-handedly must be credited with the council's decision to reverse itself by rousing public fears," said City Council member Zev Yaroslavsky, an Ezell adversary, referring to the council's change of heart after declaring Los Angeles "a city of sanctuary" for Central American refugees. Council member Ernani Bernardi, who applauds Ezell's "aggressiveness," said "he was so deeply concerned, and he convinced many other people."

Arizona state Sen. Alfredo Gutierrez (D-Phoenix) demanded last week that Ezell be fired after Ezell said the state could save $7.8 million by checking the immigration status of welfare applicants.

Sen. Dennis DeConcini (D-Ariz.) wrote to INS Commissioner Alan C. Nelson complaining that he had heard Ezell say, during a border tour, " 'Sorry, I don't have time so we can go out and chase some wets.' " The term is an abbreviation of "wetbacks," a derogatory reference to immigrants fording the Rio Grande into the United States.

"Someone that insensitive, that callous, cannot be expected to contribute to solving this volatile issue in the Southwest," Gutierrez said.

Such shock waves of notoriety were unexpected from a political appointee as obscure as Ezell was when he arrived at the pink stucco INS regional headquarters. The building on Terminal Island at Los Angeles' southern tip is only six miles from the suburban community of Wilmington where Ezell grew up. But he came to INS as a former Der Wiener Schnitzel fast-food chain executive, not an immigration expert.

At Banning High School, he lettered in four sports and was elected senior class president. He went to college for 2 1/2 years before immersing himself in a church-furniture business he started with his brother, using funds provided by their parents. After 50 years of marriage, his parents are still ministers at Wilmington's Harbor Christian Center.

Ezell had turned his attention to real estate when the hot-dog chain's founder decided he was the perfect person to select sites for new shops. Ezell was a financial success, but by 1980 was looking for something else.

He had been an enthusiastic Reagan campaign worker and an occasional low-level adviser who thought a successful businessman could teach government something about management. A flurry of transfers and reassignments followed his arrival here, but he said he also was surprised to find "very outstanding people that I think could make it, without any question, in the private sector."

He is a Lincoln Republican, born Feb. 12. Lincoln memorabilia fill nearly every inch of wall space in his large office. As his idol did, Ezell came into office believing that a strong federal executive has its place.

He also believed that the news media have their place, and he shuddered at the cornered-animal pose of Reagan appointees such as then-Secretary of the Interior James G. Watt. "I said, 'Not me,' " Ezell recalled. "I'm going to let them into the world of INS, and they can see it for themselves."

Visits to the border and exposure to the service's daily reports of increasing immigrant arrests convinced him that the story could not be overemphasized: "I had no idea of the breadth and the depth of the problem. I don't believe the average congressman or senator in Washington has a clue to what really is happening with the invasion of this nation with illegal aliens -- every day."

He found an aggravating factor in the burgeoning sanctuary movement, which by late 1985 had persuaded 270 churches and a dozen small- to medium-sized cities to offer protection to Central American refugees risking deportation.

The movement, Ezell argued, "was not really concerned about the humanitarian aspect. It's a political issue, wanting to get the Reagan administration's policies changed in Central America." He hooted in delight at a Doonesbury cartoon lampooning the sanctuary movement's apparent preference for refugees from anti-Marxist, rather than pro-Marxist, governments.

A long investigation, authorized in Washington and carrying Ezell's strong approval, led to the indictment of several ministers and church workers now on trial in Tucson for allegedly conspiring to smuggle illegal immigrants into the country. In Los Angeles, where the movement was about to add the nation's second-largest city to its smaller successes, Ezell launched a public relations blitz.

Ezell appeared at the Nov. 28 City Council meeting -- taking the most prominent witness seat within the circle of council desks -- and denounced the sanctuary idea as provocative and illegal. When the motion to declare Los Angeles "a city of sanctuary" passed by one vote, he hinted to reporters that the city might lose some federal funds because of it.

Ezell predicted that voters would not put up with it, and a petition drive to reverse the action soon began. Council members reported phone lines jammed with calls from angry constituents. Within weeks, the council had reversed itself, leaving only a mild restatement of existing policy toward undocumented immigrants with no reference to sanctuary.

"I don't think there has ever been a federal appointee before who used such hate and innuendo to arouse the community," said Yaroslavsky, who supported the sanctuary resolution.

Ezell shrugs off such assaults with the nonchalance of someone who has survived worse. His first wife, the mother of his two grown daughters, died of a brain tumor. His second wife died of lupus. He has been married to his third wife, Lee, a Christian-inspirational author and speaker, for 13 years.

If there is one charge that seems to darken his usually sunny demeanor, it is the accusation that his fight to close the border is racist. "You can't grow up in Wilmington, which is 70, 80 percent Hispanic, and not understand all people are the same," he said.

Continually campaigning for more staff to catch illegal immigrants and for sanctions against employers who hire them, Ezell complains often about Republicans who think that low-paid workers from Mexico help curb inflation and spur economic growth.

Ezell cites local studies showing illegal immigrants and their children jamming the schools, filling hospital maternity wards, causing far more than their share of local crimes. He invites a visitor to tour a well-traveled illegal crossing point to demonstrate what he considers the unassailable argument for more federal controls.

"If the capital of this nation was out on the bluff overlooking that soccer field south of San Diego," he said, "we would have had immigration reform many years ago."