Some politicians believe that a new grass-roots movement is taking shape in the United States, comparable in some ways to the great movements for civil rights and aganist the Vietnam War. The comparison was made by Sen. Edward M. Kennedy (M-Mass.) when he addressed the first national convention of the hospice movement in Washington last week - and some of his views were echoed from the other side of the political fence by Sen. Bob Dole (R-Kan.).

What is it about hospice that can stir people's emotions to the point at which two such disparate - some would say calculating - politicians feel moved to declare their commitment to the idea, and to pledge their support of the movement? Skeptics say that it is natural for politicians to climb on a bandwagon when they see one. But that view, which reflects today's widespread distrust of politicals' motives, fails to take account of the fact that they, too, are mortal, and that they react to the idea of dying in much the same way as other mortals.

The hospice groups now springing up around the country are responding to one of the deepest needs in all of us - the need to feel that when our time to die comes, we will be able to do so in conditions that reduce the physical suffering and the spiritual anguish to the minimum. In the hospice setting, the dying patient can even feel "happy" at the way a previously dreaded experience turns out to hold no terror - as our own daughter told us she was happy when she was dying in a hospice last year.

Hospice care - whether at home, or in a hospice proper, and sometimes even in a hospital - is made up of a special combination of medical and nursing skills, of psychological insights and freedom from financial worry that can make it possible for the patient to come to terms with dying. But there are still those who see hospice as a house of death. It cannot be repeated too often, therefore, that for the patient the last weeks or months spend under hospice care can be a period when he lives his life more fully, shares his feelings more intensely, gives of his own love and absorbs love from others more freely than at any other time.

The great advances made in recent years in the control pain and in easing the physical discomforts of the dying are not the only things that make the hospice way of dying more bearable. The hospice attitude toward dying makes it possible for the staff and the patient, for family and friends, to deal with the greatest crisis that any of us will ever face as something that can be managed, something that can be eased. But before that can happen, we must learn to talk about dying, to think about it, as hospice staff and patients do - for we cannot come to terms with something that we dare not even consider.

One man who visited a patient of the New Haven (Conn.) hospice recently his come away a different person because of the experience. The two talked for a few moments, and the visitor realized that the cancer patient, a man of nearly 70, felt more comfortable about the conversation than he did. "He had come to terms with the idea of dying," the visitor recalls. "I had not. I was 47 years old, and I had never come really close to someone who was dying."

That visit will have momentous consequences, for the visitor was Joseph Califano, secretary of health, education and welfare, who has since instructed his staff to devise a number of steps to ease the progress of the hospice movement, pending the more elaborate measures that can only be taken after more detailed study and legislation. The visit, Califano says, made him realize that he had been shielded from the idea of dying, that he was the product of an "enlightened" society that had banished the idea of death.

And by banishing the idea, as he now sees it, "we have too often banished the dying" - to physical and emotional isolation, to denial of reality, to unnecessary pain, both psychic and physical. He believes that because modern Americans are singularly uncomfortable with the idea of death, their ability to comfort the dying and their families is thereby diminished. HIs visit to New Haven was a turning point, because he went there with the idea that hospice was about dying - but he came away realizing that it was about living, a way of living more fully and completely, he says, embraced by human concern and support, up to the very end.

Califano's visit helped him to break the taboo. It was an intensely personal experience, but the result of it - coupled with an HEW study - will enable the bureaucracy to waive some of the restrictions on fees paid by Medicare and Medicaid for hospice care.

But that is only a small beginning. Califano was deeply impressed by the spontaneity and enthusiasm he found in the hospice movement, and he is concerned about the danger of upsetting the delicate machanism of private and voluntary effort by federal intervention. "Our challenge is to nourish this movement," he says, "not to force-feed it."

It will be up to Congress to decide what constitutes adequate nourishment. This is where the pledges of such men as Kennedy and Dole assume a particular importance. The imperatives of the political and budgetary process rarely coincide with the dictates of the heart. But private charity can hardly meet a huge need. A year ago there were only a few dozen hospice groups in various - mostly early - stages of development in the United States, and today their number is nearly 200. Before long every sizable community will want one.

There are dangers in too-enthusiastic, too-rapid development. But there is pain and suffering and anguish in every avoidable delay. One in every four Americans will eventually have cancer - 390,000 will die of it this year, more than 1,000 a day. We are spending billions on trying to find a cure, but a small fraction of that money, spent on hospice, could make many of the deaths, which we know are inevitable, less harrowing than they need be.