The ayatollah got Jimmy Carter. The economy got Jimmy Carter. Ronald Reagan got Jimmy Carter. Jimmy Carter got Jimmy Carter. You pay your money, you take your choice: these are the theories floating around, and there is something to each of them. But I think public relations got Jimmy Carter -- the tireless and doomed pursuit of an effective image, a winning voice, the right set of symbols to project. He came to office, in large part, because all these systems were "go" in his 1976 political campaign. He couldn't keep them adjusted to the office and the times and the issues. And, what with his pollsters and his image-makers, he was seen to be trying too hard. Carter worked at it like the devil, but he could finally never acquire that quality of authenticity in his communications with others from which presidential authority flows.

Nobody ever said it was easy. We are a country, a political culture that natters on endlessly about "communications," but which has all but lost both the opportunity to communicate and (even) the gift of speech. Our basic unit of discourse is the press release, and the basic talent of our leaders lies in talking into machines -- that is, into the peopleless electronic void -- as if talking to someone. Emotion, candor, chemistry do not exist in these "exchanges." They are exchanges between a president and his idea of who is listening.

That is part of the problem. Another part is that we not only expect a projection of the right symbols -- and thus values -- from our presidents, but also walk around with mutually contradictory ideas of what these values are -- grandeur plus cottage-hearth simplicity, for example. The final cruelty lies in the fact that having demanded all this from a leader who is, of necessity, doing a public-relations number, we invariably see through the fakery of it all -- and then we rage.

As this coldhearted town ushered Jimmy Carter out and welcomed in his successor, I couldn't help recalling the whole progression of poses and postures. Jimmy Carter thought, because we had given him to believe it, that what we really wanted was the suit bag slung over the presidential shoulder -- the walk down the inaugural route, the designation of the Washington limousine as public enemy No. 1, blue jeans and dosi-dos in high places, the cardigan, the anti-imperial, unassuming presidency.

He staged this presidency doggedly and without cease for us. There was your president being broadcast while taking telephone calls from citizens about their homely problems, promising to get in touch with the right branch of the bureaucracy to straighten out the foul-up. There he was overnighting with your average family and the caption was always pretty much the same: he said he understood the particular dilemmas of this nice family, and what's more, he made his own bed!

Jimmy Carter was being set up by the whole 200 million of us and he didn't seem to know it. We wanted a president who didn't make his own bed, in addition to one who did. And, besides, the staginess of the whole thing really got to us. That day, just before the election when he flew back to Washington from Chicago, because of a flurry of hostage activity, and was handed a document when he got off the helicopter, which he proceeded ostentatiously to read as he walked across the lawn, was a perfect, eleventh-hour example. I thought, watching it that Sunday morning on TV: But this is hokey. This is contrivance. Am I the only one who notices it? No -- everyone, everyone who is watching this bit of stagework knows what it is and is made at least somewhat uncomfortable, if not downright resentful, by it.

I cannot say that I think the antidote or proper reaction to the Carter presidency's cultivation of this imagery, especially its humble-citizen affectation, is the morning coat and the 5-mile-long black car and the magnum of chilled bubbly. That would be nothing but one more predictable swing of the pendulum that, invariably, on its next swing knocks cold whoever was taking advantage of the current reaction or trend. And that, surely, is one thing that Ronald Reagan can profitably consider when he is thinking about the fate of Jimmy Carter. But there is really more to the public-relations trap than that. There is more to be learned from how it got the 39th president.

Maybe the hardest and yet most essential thing for a president to do in this day and age is to find his authentic voice and to -- forgive me -- communicate it to all his various publics, clients and antagonists. We stack the odds against him. We tempt him to do other things. But basically this is what people are after, and it is also the crucial instrument of presidential policy success.

Presidents can't make many things happen. They can make news and noise, but these merely create an illusion of achievement, and when they subside not much will have changed. Arguably, in fact, Jimmy Carter may ultimately have more impact on this country through the federal judges he appointed than by anything else he did. But what little a president can do in the realm of foreign, economic, defense and social policy requires as a precondition that he speak with plausibility and authority to the country and to those it does business with.

This, in turn, can only be the product of tremendous acts of will, political self-denial and shrewdness. A president needs to speak in a idiom and relay a message that at once certifies his own common humanity and his uncommon mastery of turmoil and complication. It's got nothing to do with pandering to the presumed changing fashions of politics, nothing to do with constant temperature taking and (equally) nothing to do with imperiousness or playing De Gaulle on Pennsylvania Avenue. Integrity, consistency, magnanimity and a kind of tough insistence on sticking with what you have determined to be the right way -- all this goes into the authentic presidential voice, is heard in it.

Jimmy Carter once knew this. Something -- or someone or some array of circumstances -- knocked him off it. Ronald Reagan could do worse than to ponder what happened then.