He grew up in the Midwest and acted in a series of minor roles. He became increasingly vocal in entertainment industry politics, eventually turning to national issues. His first marriage ended in divorce, and he was elected president of the Screen Actors Guild. His name is often associated with political issues. It is not Ronald Reagan.

Ed Asner was in town again yesterday, doing what he has been doing more and more of: speaking out, raising money, lending his household name to one cause or another. The actor as activist. This time it was El Salvador. Asner, Lee Grant, Ralph Waite, Howard Hesseman and Bert Schneider made the pilgrimage from Hollywood to the State Department yesterday, to present a check of $25,000 to Medical Aid for El Salvador.

Before that, they held a press conference at the Capital Hilton. Asner was clearly the center of attention in the room packed with people and cameras: Never mind the Mexican doctor who told about 11 of her Salvadoran students killed by the military, or a visibly shaking, misty-eyed Lee Grant, or Ralph ("Pa Walton") Waite declaring "our leaders are lying" to the American public. Asner was the most articulate and the most politically savvy. "We have other people here," he said. "Please do not address all the questions to me."

But there is one question that is hard to resist asking, a question drawn from Asner's frequent trips to Washington and trail of political platforms. Would he seek public office?

Asner paused significantly before answering, when the question was asked during another visit for the recent Franklin Delano Roosevelt centennial. He looked furious, his bottom lip protruding, cheeks puffed out, like he might explode in outrage.

"NO. Well, you have flights of fancy. And then I finally sobered up and they became nightmares. I would not like to run for public office at all."

Then why the politicking?

Another incredulous stare. "Regard it as public service announcements."

Asner -- so closely identified with his successful television show that he was introduced as "Lou Grant, er, Ed Asner" yesterday -- has emerged as a political beast. His sincere-looking, gruff mug is turning up in magazine and TV ads, at fund-raisers and demonstrations. During the past few years Asner has lent his name to the ERA, the Freedom of Information Act, Ralph Nader's consumer organization, Public Citizen, and most recently, El Salvador. He has called himself a "union loyalist" and a "staunch unionist." He was an outspoken critic of the House Select Committee on Narcotics Abuse and Control, charging the panel with opening a vendetta similar to the anticommunist crusade in Hollywood in the 1950s. He was among the leaders of the recent actors' strikes and last November became SAG president.

Asner defends the human race with the same ferocity with which he protects his fictional reporters on prime-time television. During FDR weekend he complained, perhaps facetiously, that he isn't given enough to say on "Lou Grant" because the program concentrates on the reporters. "Due to the nature of the beast, as an editor, it's very difficult to get stories centered around me . . . So then I all too often have had to take a back seat in the presentation" of issues.

"I delight in the issues we deal with," Asner said. "I long for greater activity in the presentation of them."

Asner seems afraid only of being afraid to speak his mind. "I'm quite comfortable and believe I have an ability to speak out, perhaps sometimes too rashly, but I think in this day and age there are far too many who don't speak out at all. I would consider it an attribute."

Before the success of "The Mary Tyler Moore Show," when he was a relative unknown in entertainment and politics, he remained quiet because, he said, he was too insecure about acting roles and income. "There were vestiges of fear that dominated," he said. When did he become politicized? "When I was born. But I began shooting my mouth off four or five years ago." Now, it's the actors he represents in the SAG who are insecure and afraid. His job as its president, he said, is to find work for the 90 percent unemployed.

But even SAG president plays second fiddle to political humanist. Yesterday someone dared ask Asner if he would seek contributions for Medical Aid to El Salvador from SAG members. Again, he looked like he might explode. "What paper are you from?" he asked the reporter. "I'm here as a private citizen. I will not ask for one penny" from the guild.

Meanwhile, Asner keeps defying his fear of indifference as he did on a previous visit:

* El Salvador: "I'm trying to get this country to stop its gringo participation in the fate of El Salvador or change its age-old nonattention to the problems of Central America, which are true land reform and true democratic practices."

* ERA: "It is necessary to keep chomping and stomping about ERA, not necessarily for this battle since I tend to think this one will probably be lost, but to immediately begin the onset for the next passage of ERA. Because it will be passed."

* PATCO: "I certainly have not been the ideal spokesman for PATCO because I have flown . . . I primarily became identified with PATCO not because I so identified with the particular miseries of their strike. But I thought, 'How horrendous that the establishment in this country, including the press, had so totally condemned them.' "

* Poland: "Poland is very safe. It's a wonderful unifying thing for both conservatives and liberals."

Asner said he hasn't "the vaguest" notion of how much longer the "Lou Grant" show will continue, said the only other thing he'd like to do beside acting is "read" and would try directing "only if I got too bored with acting, or couldn't get acting jobs." Yesterday he announced that he and his colleagues in entertainment would play an increasingly active role in political matters, that they have no expertise, it's true, but "we are all American citizens and our visibility gives us a special responsibility."

And does he think that in the process they're losing their identities as actors? "I hope to furbish my identity as a concerned human being," Asner said. "If it costs the actor, then so be it."