This campaign is beginning to remind me of the diet I've been on for the past 38 years. A fair-minded person would have to say it doesn't seem to be working. And, worse, it doesn't seem to be working because of the same old flaws. If I had to choose a single controlling weakness that has corrupted our political campaigns in the past and already threatens to ruin this one, it would be this: we have no collective memory, none. If it happened more than six hours ago, it is gone. Thanks to this particular memtal impairment -- shared by politicians, press and public alike -- our candidates, continuously recreating themselves, don't seem quite to exist, and their arguments don't seem to be about anything.

Last seek's squall over the presidential debate and guest list illustrates the point nicely. Somewhat worried about the inevitable catcall reaction to the president's initial decision not to take part, Carter's people nonetheless were confident that, if he stuck with that decision, everyone would have forgotten about it in a couple of weeks. They kept saying as much, and there is no reason to think they didn't believe it.

In fact, it is hard to think of a compaign that has reposed more trust than the president's in this odd American habit. There, after all, was Carter -- the fellow who appeared on the cover of both Time and Newsweek in 1976 on the basis of having won less than a third of the votes cast in the Iowa caucus and the New Hamshire primary -- protesting that John Anderson had not won enough votes this year to deserve his media coverage. And there is Carter, the 1976 promiser of a cut in the Republican defence budget, now claiming that the Republicans had let that budget sink so low that he, poor devil, has been obliged to strive to build it up.

And now here is the Carter administration making a big and portentous "thing" out of the fact that Ronald Reagan and his chief economic adviser disagreed over whether we are in a "recession" or "depression." Evidently Carter's men are confident that their sporting with this disagreement will not remind people that similar disagreement between Carter and his inflation advisor, Alfred E. Kahn, led to Kahn's announcement that hereafter he would use the word "banana" when he meant the(forbidden) "recession."

Merely to cite these things is to invite several complaints. One is that "everyone does it," so that it is unfair to single out Carter. This is true -- even though Carter does it with a straight face and straight gaze and moral earnestness that is downright astonishing. But it is also the case that John Anderson, the remade liberal centrist, has taken flight from an earlier personality, and that Reagan, even if only a quarter of those old quotes of his are accurate, has come from someplace pretty peculiar to his normality of today.

I suppose it can also be argued that it is wicked to dwell on these skin sheddings and related changes or to denounce them because they are, in some way, evidence that our leaders are responsive to us and capable of growth and change. But this, of course, is nonsence, since what we are talking about is the candidates' whipping back and forth among contradictory positions and views, serene in the knowledge that a lobotomized public and press will not remember where they were the year or month or day before.

The press is especially important to this phenomenon. We like to affect a we've-seen-it-all-before cyncism in relation to campaigns (and, alas, we have), but we never seem to able to remember just what it is we have seen and apparently lack the energy to try. In off years, not just political ones, we go from fascination to fascination and, having pronounced some turmoil or scandal or contest the most important thing in the world, eventually just walk away from it. I assume, for instance, that the "welfare crisis" is still pretty critical for many people (and many state coffers), but it has gone. So have the Indochinese "boat people" and other refugees. Though luck, baby -- see ya around.

In political years this attribute reaches truly spectacular proportions. It is we who permit, even encourage, the candidates to keep refashioning themselves before the nation's very eyes, announcing (breathlessly) each new turn, fixing (momentarily) on each new trendy perception and then abruptly moving on. Two weeks from now, the candidates can be confident, it will be forgotten -- it doesn't matter whether "it" is postal theft, stupidity or matricide. We -- here we are joined by a much larger community than just the press -- even consider it rather dirty pool to "bring up" things that happened in the past. Chappaquiddick, after all, required a whole lot of apologies and disclaimers on the part of anyone who even mentioned it during the pimary campaign. To do so was a personal foul.

What this says to me is that we justdon't know how to think about the past and so we try not to. Sometimes we dredge up, as the candidates have done, great compilations of awful sayings (e.g., the Reagan compendium on display at the Democartic convention). But it is characteristic that these -- awful as they may be -- are just fired off in rat-a-tat salvos, without context or explanation. Did you know that he once said. . . There is no when or how or why though conceivably this could make the whole thing sound even worse. They are, instead, one-shot doses, history without any historical meaning.

I think this is why this country's political campaigns, especially its presidential ones, have the aspect of an animated cartoon when the projector has gone haywire and the whole squawking, shrieking thing is even more frentic than usual. People who run for office have no past, except the one that they try to hide and that the other fellow tries to hit them with. So they don't seem to come from anywhere or to be anyone, besides, that is, whoever the crowd of the moment hopes they will be. It is all a bunch of "lashings out" and "strikings back" and this one "charged today" and that one "counterattacked with" -- and, finally, who cares? It is exciting without being intersting, which is what happens when there is neither memory nor history nor whole people nor even any sense of time.