Here in the heartland, as the pundits like to say, Edward M. Kennedy for the first time faced a judgment by voters outside of Massachusetts. Before the first ballots had been counted, a different kind of verdict already had been rendered on the third of the Kennedy brothers to seek the presidency in the last 20 years. It represented the puncturing of a myth that has encased American politics for a generation.

The tabulation coming in throughout Iowa last night, showing Kennedy being swamped by Carter votes, only reinforced the difficult political situation confronting him.

Just a week ago, for instance, there formed one of those scenses that politically incestuous Washington loves -- a gathering of the mighty assembled to pay public tribute to the passing of a true power broker. The occasion was the funeral of George Meany.

It might as well have been a state funeral for the range of prominent people invited. The lines were long, the day was dismal, and the movement inside St. Mathew's Cathedral proceeded slowly.

On the steps out front, a group of senators stood to the side in a light drizzle, talking. It was, one of them said later, like an impromptu Democratic caucus; they had been back to their home states over the Christmas congressional recesses and had not seen each other since.

One topic dominated their conversation and it had nothing to do with George Meany or the American labor movement or the hostages in Iran or the Russians in Afghanistan. It was what had happened to Teddy.

These were his peers, the representatives of politically crucial states in every region of the country. Nearly all of them had favored Kennedy over Carter, and a number had urged him privately to run.

Their collective judgement, as given state by state, was that Kennedy would have been badly beaten by Jimmy Carter had the presidental election taken place that day. Only one senator, from a southwestern state with a large Chicano population, thought Kennedy would carry his state at that moment.

As realists, aware of the volatility of voters and the unpredictable nature of events at home and abroad, they did not consign Kennedy to ultimate political defeat. But they did muse aloud over the confounding turn of fortune that has overtaken the last Kennedy and his campaign.

As one of them said afterward: "I must say I have viewed Ted's campaign with something like a sense of shock. I was certain last summer that when he began running in the fall he would take off like a comet, that nothing could stop him.

"He's been thrown off his stride in ways I can't understand, and I think it's as much personal as with the other events that have happened."

They were directly addressing the extraordinary change in Kennedy's prospects since he announced his candidacy only 10 weeks earlier. In a larger sense, they were laying to rest the legend.

Their chance gathering at St. Matthew's had elements of high symbolism: It was there, little more than 16 years before, that the Kennedy myth first flowered.

Standing then on those same steps, in a scene graven into the American consciousness, were the mourning Kennedy family members, their faces ashen, their manner resolute, watching as John Kennedy's coffin was placed on a caisson for the final journey to Arlington and the lighting of the "Eternal Flame." When 3-year-old John-John raised his right hand in salute to his father from those steps, the romance about Camelot -- with a mighty assist from the media -- was not long in taking hold.

Whatever occurs to Edward Kennedy, starting today with the citizens of Iowa, the politics of 1980 mark the end of all the political talk about the inevitable invincibility of the "Kennedy political juggernaut."

Kennedy begins his test with the voters, fighting on two critical fronts: To regain lost ground against the president and -- in the most difficult battle of all -- to fend off the personal assaults on his character that keep surfacing.

After all the blows that have befallen Ted Kennedy since the beginning of his campaign, it comes as something of a surprise to see him in action.

Kennedy on the stump today is markedly different from the Kennedy of two months ago. Today, he delivers a superb political speech, crisply and confidently, handles questions adroitly, draws enthusiastic responses from audiences, and campaigns with what appears to be obvious enjoyment.

There's no faltering, no fumbling, no vague wandering from issue to issue. He and his advisers have honed a coherent political attack on the president's domestic and foreign policies that reaches an emotional peak when Kennedy pounds the lectern and shouts, "Enough is enough."

His campaign entourage, far from being awash in gloom, is both looser and more assured; the tone is definitely upbeat; technically, the campaign functions smoothly. One gets none of the corrosive sense of the loser that takes hold of campaigns sinking in the polls and in obvious distress.

Kennedy himself talks coolly about his effort. There was a time before Christmas, when some people who saw him privately found him frustrated, snappish, down.

When one of his political contemporaries asked how it was going then, Kennedy raised his hand high and then dropped it downward in a long descending arc, saying: "Whoooosh!" Another who brought him hard political news encountered a flash of anger. But such displays, too, seem to have been absent in recent weeks.

Now Kennedy speaks with a certain detachment, and with humor. He blames himself for his poor start. When he made his decision privately to run last summer, he was thinking about announcing in December. But as weeks passed, he found himself increasingly uncomfortable playing a coy political game.

Once having resolved his questions about why he would run and not wait another four years, he wanted to make a clear break. That did not permit adequate time to form his political team and fashion his political approach. At that, his campaign began with much less chaos and confusion than had his brother Bob's.

Kennedy has been experimenting with his speaking style, and it shows. Now, when appearing on TV or radio, he has learned to sit more quietly and speak more slowly. He comes over more as a "laid-back" candidate of the 80s. Before live audiences on the trail, he's done something alien to the oratorical traditions from which he sprigns. In the midst of his set speech, he reaches down and holds up large graphs, taking time to explain what they mean about -- among other things -- oil prices and profits.

It's here that he gets one of his best crowd responses. When deriding the president's decision to decontrol oil prices so as to allow the oil companies to use their additional profits to find new supplies, he remarks that Mobile Oil Co. took part of its new wealth to buy Montgomery Ward.

"Now how much oil do you think Mobile will find drilling in the aisle of a Montgomery Ward department store?" Kennedy calls out, to a roar of approval.

And Kennedy speaks, privately at least, of a belief that new life and new vitality are coming back into the political system this year. Yet with all this, he still can't escape the single issue that dogs him everywhere and that he cannot seem to put to rest -- Chappaquiddick.

Riding in his car toward an airport heading from one Iowa stop to another the other day, only once did Kennedy show a sign of anger and emotion while talking about his political campaign. It was over the latest spate of stories in The Washington Star and the Reader's Digest raising new questions about Chappaquiddick on the eve of the Iowa caucus voting tonight. He flared,his face reddened, and he dismissed the stories as scurrilous, politically motivated, and completely irresponsible journalism.

But his words and his answers have not stemmed such stories, which grow more poisonous with time.

From the beginning of his campaign, Kennedy has dealt repeatedly with questions about his relations with women and about Chappaquiddick. Raising them was inevitable, as the Roger Mudd interview demonstrated.

But since then, as Kennedy's political approval ratings plummeted during the Iranian situation and Carter's rose, the reports have taken on an uglier tone.

Last month saw the publication of an article in The Washington Monthly by Suzannah Lessard, who writes for the New Yorker, entitled, "Kennedy's Woman Problem, Women's Kennedy Problem."

The piece had been first commissioned by The New Republic, but that magazine (and later The Washington Post) would not print it. The story made the assumption, without documentation, relying on hearsay anecdotes and with no attempt to prove its case, that Kennedy was a philanderer. ". . . Despite our distaste for going into this sort of thing," she writes, "our reluctance to judge others, and the importance of the principle of privacy, Ten Kennedy's reputation as a philanderer should be publicly discussed as a legitimate issue in the campaign."

Thus, the "reputation" becomes the issue.

These kinds of stories reached a low last week when The New York Post published stories under banner headlines about "Ted kennedy's secret PARTIES," detailing the 11-year-old memories of a phony countess who claims to have had a two-year affair with Kennedy that supposedly began on Martha's Vineyard, and may, she says -- but can't be sure -- have included a stay on Chappaquiddick.

If correct, this would indicate Kennedy wasn't telling the truth when he said he had not stayed on Chappaquiddick before that fateful summer weekend a decade ago.

Such a story represents more than the outpourings of the current scandal sheets; it reflects a blood-in-the-water syndrome that has the sharks circling the Kennedy presidental campaign.

Again, strangely enough (or perhaps not so at all) Chappaquiddick has not dominated Kennedy's campaign travels. He's been asked about it only a dozen or so times in more than two months on the road.

His aides take the view they can do nothing about the stories anyway; that the answer is to keep campaigning and to believe that, in the end, the stories will prove to be self-defeating, offensive to the public's sence of fair play.

That question will only be answered when voters begin to give a judgment on Kennedy tonight and in the primary days immediately ahead. But there's no doubt that these personal factors have made this early stage of the latest Kennedy campaign unlike any other -- and different from most others in our history.

Some of Kennedy's Senate colleagues, watching his campaign unfold, think some of his early problems may stem from Kennedy himself becoming entrapped by the Kennedy mystique of invincibility.

He spent 12 years agonizing over if and when to run, and at what consequences to himself and his family, but without clearly thinking through why he wanted the job and how he would win it. This, at least, is a view shared by a number of persons who have watched him closely over the years.

It's only speculation, of course, but it would be understandable if Kennedy harbored some such illusions. After all, virtually every political sounding for more than a decade made him the top-ranked individual in his field, the people's resounding political choice. The question was not if he might become president, but when.

The Iowa votes tonight seriously cast in doubt the Kennedy camp's hopes that his current political weakness would prove to be transitory. Yet others, in earlier campaigns, ahd begun at least as far behind and had run as poorly, it was being said. Dwight Eisenhower, at a far later stage in his presidential race, was being lambasted by his supporters for his fumbling, inept candidacy and criticized publicly by such strong backers as the Scripps Howard newspapers for "runninglike a dry creek."

Kennedy's own private political samplings, along with those of other candidates, show Jimmy Carter still highly vulnerable politically. Kennedy's people can cite polls showing that better than two out of three people find reasons why the nation would be better with Kennedy as president; that Kennedy still rates higher than Carter on effectiveness, competence, strength and experience.

In such samplings, Carter wins personally but loses professionally. But at this moment the reverse is also true -- that Kennedy wins professionally and loses personally.

All that, of course, was before tonight's voting here in Iowa.

However the citizens of Iowa and other states resolve that quandary, something else already has been decided, even before the first votes are cast here tonight.

The Kennedy myth of supernatural political strength has been shattered. That surely can only be a sign of healthy realism -- both for the country, and for Ted Kennedy.