IT IS SOMEHOW appropriate that at the end of his second year as president, Jimmy Carter has taken up the running fad. The White House recently has made available pictures of the jogging chief executive, his hair pressed back against the wind as he circled the spacious south grounds of his residence. It is also predictable that the president took to runnin in a singularly passionless way - not, like so many others, of the joy of it, but because it is efficient.

"It's not time consuming," he told Sports Illustrated. "I can go out and run, for me, a fairly fast two miles in about 15 minutes or run three miles in 25 minutes or take a slower pace, 10 minutes to a mile, and run seven miles. Then I can come back in and go back to work shortly."

Much of the two-year Carger presidency is summed up in that quote. There is the grim determination to suceed in yet another undertaking. There is the cool calculation of performance. And, always, there is the drive to "go back to work."

But there is not much in those words to stir the hearts of other long-distance runners.

It is much the same with the Carter presidency. After two years in the Oval Office, the president can look back on some solid accomplishments. He has done many things better, certainly, than a good number of his predecessors.

What he has not done, and may be incapable of doing, is to stir the imaginations and emotions of his countrymen. And because of that, he seems to many of us still a fragile and vulnerable political figure, still something of a stranger in the land he was elected to lead.

We in the press and the other "establishments" he ran against in 1976 parcel out our praise of his achievements in grudginly small doses. We are waiting for him to stumble again, as he did so badly at first, so that we may pounce.

Carter has nothing remotely resembling a core of sympathetic friends, let alone a "cheering section," among the powers of the media. No doubt this is largely a function of the times. After all the disillusionments produced by other presidents who had their cheerleaders, it is not surprising, and we are better off in the long run because of it.

What is surprising is that a man like Carter, who seems so obviously well intentioned and hard working in the pursuit of generally sensible goals, should have after two years barely dented the post-Vietnam, post-Watergate cynicism of the press.

Nor is what David S. Broder has described as the "emotional vacuum" surrounding the Carter presidency confined to the professional cynics of the press. If there is in the country, outside the president's immediate circle of family, old friends and top aides, a sizable cadre of passionately pro-Carter Americans, it has escaped my attention these last two years.

The phenomenon reaches even inside the White House. A Carter associate a thoughful and sensitive observer of such matters - remarked recently that among the middle-level professionals in the White House, there are any number of young men and women simply "marking time," waiting for these next two years to pass so that there is a logical and impressive conclusion for their resumes. This friend guessed that, outside the preident's fiercely loyal senior aides, Carter enjoys less personal loyalty from a junior staff he almost never sees than any of his recent predecessors. A National City Manager

OTHER PRESIDENTS, and other policians, have had their emotional allies and passionate enemies. Carter seems to have neither. Other presidents have been able to make us laugh and make us cry. Carter seems incapable of either.

To some of us in the White House press corps who covered him, Gerald R. Ford was known as cthe Bonz," a name meant to convey the aura of benign clumsiness that seemed to accompany so much of what he did. It was a term of ridicule, to be sure, but also a term of affection. No such nickname attaches to Jimmy Carter.

I don't exactly know why this is, but I suspect it has something to do with being the kind of man who runs because it is not time-consuming. The first time I saw Jimmy Carter-it was September 1976 - the most striking image was the calm, even coolness, that surrounded his campaign appearances. The cnadidate spoke softly and dispassionately. His audiences listened attentively - a reaction Ford did not always enjoy - but with little of the heat and excitement presidential political rallies usually purdece.

The president seemed than, as he does now, to ask only one thing: to be judged by his achievements ("competence" is what he promised then and now) and by his integrity and intentions ("compassion" was and is the code word for that).

He did not promise to excite us or entertain us or even "lead" us in the public fashion of a Franklin D. Roosevelt, John F. Kennedy or Lyndon B. Johnson. He promised only to manage our affairs sensibly and with a degree of charity. We in turn responded, and so elected the country's first national city manager.

Is that enough? Along with all the other variables that go into such a close election, it certainly was enough in 1976. But times, and the temper of the American electorate, change. And Carter, having failed to establish much of an emotional bond with the American people these last two years, seems particularly vulnerable to a change in the national temper. Little Margin for Failure

THAT FEELING - that whatever his accomplishments Carter will remain a curiously vulnerable figure - may explain in part why we in the press made such a fuss over the speech Sen. Edward M. Kennedy made Dec. 9 at the Democratic midterm conference in Memphis. Kennedy reminded us that there is still a human quality known as charisma and still a place in American politics for fiery oratory and deeply felt emotion.

Politicians who can do that make their won breaks. When Kennedy provoked wild cheering with his warning about domestic budget cuts and his call for national health insurance, he was speaking to an audience of committed Democratic liberals, hardly a cross-section of American voters. They were clearly his people, gathered at a workshop session to hear and respond to just such a speech. But few of us, myself included, noted that in our dispatches from Memphis.

Politicians who grip neithe rour imaginations nor our emotions don't get those kind of breaks. Should Jimmy Carter, in some almost inconceivable circumstance, provoke a similar crowd response, the makeup of the audience probably would be subject to closest scrutiny, down to the number of Georgians, ex-Georgians, other southerners and government employes among its numbers.

Having offered so little in terms of emotion and inspiration, the president gets little in return. That makes him vulnerable, cruelly and unnecessarily vulnerable for a man with his record in office.

Against that vulnerability, he has only one defense. He must continue to "achieve," to produce the requisite number of "victories," both real and imagined. His first year he failed to do that and he paid the price. This year he did better and the voices of his critics were clamed, if only temporily. The next two years remain uncertain, with no lack of problems to confront and pitfalls to avoid.

Whatever happens, he can never let up. So long as he has a string of "victories," he is relatively safe from the emotional winds generated by a Kennedy. But he has relatively little margin for failure - for an episode, to cite an example that comes to mind, like the Bay of Pigs.

He must keep on running, trimming the seconds off the miles he covers, ever mindful that in his kind of presidency he is likely to be judged as he has asked to be, coldly, on the basis of performance alone. He has nothing else to fall back on.