Somewhere between the eighteenth and the eightieth analysis of New Hampshire last week, I had a terrible revelation.It is that we in this country give over approximately 20 months of every four years to explaining to each other why our political predictions of the day before were wrong. But this is not the terrible part. The terrible part is that these explanations and post-mortem accounts tend to be, if anything, even less plausible than the failed predictions they are meant to explain. It's not just that people don't do what we assume they will -- it's worse: they don't not do it for the reasons that we cite the morning after. This, of course, guarantees the next set of failed predictions, and ensures that political analysis will thrive.

We are in the presence here of something more considerable, even eternal, than the 1980 Kennedy/Reagan will win, will lose, will win, will lose thing. Goldwater was too marginal to be nominated in 1964; Nixon by 1967-68 was finished; McGovern was too radical in 1972, just as Carter was too obscure, too nobody in 1976. We are forever surprised, but even so, never at a loss for an over-the-shoulder insight into where we went wrong. These insights have an average durability of an hour and 20 minutes.

The "we" I am so casually throwing around is meant to be generously inclusive. It takes in the pollsters and the polled, the candidates and the voters, the professional pols and the bystanders and -- yes -- prominently, the press. For although we journalists cover these episodes in swarms and report them to death, it is so rare for us to call them right that the few who do become legends in their own time. Four years later, we still talk about the fellow who called Iowa for Carter in '76, the way boozy old trade unionists might sing, "I dreamed I saw Joe Hill last night" -- reverently, with romance.

Why is this? Primarily, I think, because all of us -- press and politicians and voters -- insist on complicating the process unnecessarily and trusting everything but the evidence of our senses and the strong beat of our own impulses. You and I understand -- the shared confidences go -- but they (all the others) don't.

It is interesting to me in this connection that I have 1) never seen a political debate in which there was not, self-evidently, a "winner," and 2) never seen one in which the accumulated wisdom after the event did not hold that "no one won." (It was, as I recollect, The Wall Street Journal that broke through this decorous hypocrisy after the first debate in 1960 and said that far from there having been no winner and no loser, Kennedy had skunked Nixon and everyone knew it.) In this year's Manchester debate, George Bush looked tinny and Reagan looked pretty good. You knew it, and I knew it, but we figured they didn't. So there was "no winner."

Not trusting our own observations, we incline to elaborate theatrical theories instead. We turn these contests into second-rate screenplays, assigning everyone a part. Here the candidates themselves add immensely to the illusion on which assumptions are then based. They talk about themselves as if they were someone else. "We're trying to figure out if I have to get more on the offensive or what," George Bush vouch-safed to the press after New Hamsphire, even as Howard Baker was saying that since Bush would have to regain "momentum" and Reagan wear "his new front-runner crown," he, Baker, would have to play "The role that is left to me . . . to be the voice of calm and reason."

When the candidates themselves regard the performance as a kind of fiction, a fabrication of motives and results, it then becomes one. Surely, Kennedy conveys an element of this in the semiparody fashion in which he laughs out the ritual false lines about defeat being triumph and the rest. He knows, and he conveys by his transparently hokey, off-pitch manner, that he knows. This bravado of Kennedy's looks manic and crazy to some. But to me it looks like reason-saving ridicule, a joke between Kennedy and himself, an acknowledgment of pretense. I find it much more reassuring, for example, than John Connally's sober, straightforward presentation of a case for his own success to date that is entirely mad.

I do not pretend to understand Connally's campaign. It has the look of an expensive appliance that someone forgot to plug in. But when I observe him on the tube, looking perplexed and impatient to be among the other candidates at all and as if he believes he should be named to the office and now, I can fathom why he is not setting the Republican world on fire. And when I listen to Reagan, whose views are not -- to put it mildly -- mine, I can see something of his appeal and his attraction. This has the advantage of relieving me of the obligation of coming up with or adhering to some crazy screenplay theory.

Most of the journalists I know and mch of the Eastern world I live in find Reagan's candidacy preposterous. He is to them what Margaret Thatcher was to many in the British electorate for years -- the ultimate menance, what would get you in the night if you didn't eat your carrots. And this predisposition is self-perpetuating, since it calls for ever more complicated and implausible explanations of his appeals in order to explain his success.

Something at least vaguely similar, if not entirely comparable, is going on in relation to Carter-Kennedy. I don't think Carter's early showing of strength comes from some mindless and reflexive burst of patriotism or loyalty to the chief in time of trouble or anything like that. I think Carter is very vulnerable, but that his areas of vulnerability are those where Kennedy himself is weakest and least persuasive, and Kennedy's campaign has been pretty bad. We thought he would be stronger, better. Now we are seeking to explain his bad start as, somehow, the ayatollah's doing. I think a different style of Democratic opponent, coming at Carter from the other side, would have done much better. The Republicans now seem eager to provide one.

I have a way-out theory of what happened in New Hampshire last week: I think that for the moment, anyway, Reagan and Carter looked better -- more reasonable, competent and authentic -- to their parties' voters than the other guys did.