ON THE MORNING before the inauguration of William McKinley, when he and his numerous relatives were staying at the Ebbitt House, his pioneer-spirited mother was steadfastly unimpressed. She was not convinced that her son was really bettering himself by taking such an office. In fact, another of her sons had to plead: "Mother, this is better than a bishopric." (Abner McKinley was not unlike Billy Carter.)

One is not at all sure that, five presidents later, it seemed better to Calvin Coolidge. His memoirs are perhaps the most revealing and certainly the most delightful of any president.His chapter on his education at Amherst runs to 42 pages, which is exactly twice as long as the chapter, "On if realizing that this may disappoint some people, he adds another brief chapter, "Some of the Duties of the President," which might be the report of a retiring church deacon.

He is most enthusiastic in his description of his breakfasts: "fruit and about one-half cup of coffee, with a homemade cereal made from boiling together two parts of unground wheat with one part of rye," plus a strip of bacon "which went mostly to our dogs." He tentatively makes his most adventurous proposal: "I am convinced the government should own a private car for the use of the president when he leaves Washington," although he himself had used one only once, "for the better comfort of Mrs. Coolidge during her illness."

Is there not something in all of us which sighs for such days and indeed for such a man? The perspective. The proportion. The size, which is our own size. And also the dignity. "It has never been my practice to speak from rear platforms," writes Coolidge. "The confusion is so great that few people could hear, and it does not seem to me very dignified." He says that he did so only once, "at Bennington in September of 1928, where I expressed my affection and respect for the people of the state of Vermont."

But then it had not been many years before that Lord Bryce had written, "It is thought bad taste for a president to deliver stump speeches, and Andrew Johnson injured himself by the practice." How far away and attractive it all seems, not only from the turmoil and agitation of an election now, but from the indignities to which any president wishing to be reelected is today persuaded and willing to submit himself.

Coolidge was concerned that people at a whistle stop did not really listen to what he might say. But in our own time we have had James Fallows, when he was still speechwriter to President Carter, telling us that "people are less interested in what the president is actually saying" than in the media event. We have had Jody Powell telling us: "Television may not be too deep, but it's broad as hell." We have had Jerry Rafshoon summing it all up; "All politics is marketing." Coolidge was too fastidious to be marketed.

The last presidential candidate of whom this was true was Eugene McCarthy. Because he was opposed to the war in Vietnam he was mistaken by some for a radical, athough his opposition to the war (like that of many others, such as J. William Fulbright) was that of a conservative, and the good reason for voting for him in 1968 was that he would have been a president much like Coolidge.

The business of America is business, said Coolidge. The business of America is jokes, echoed McCarthy. He has often been criticized for the almost lackadaisical way in which eventually he pursued the presidency. Yet this was the man. This was the kind of politics in which he believed. When he said after his victory in the Oregon primary that he would pull down the railings around the White House, everyone took this as a wonderful commitment to open government, but what McCarthy meant was that he would make the presidency so unimportant that no one would want to go to the White House and bother him.

He was America's most recent, and perhaps its last, chance of having a conservative president. Richard Nixon was an obsessive doer.There was a revealing vignette of him when he suddenly returned alone to the White House one night during the New Year holiday of 1974. Early in the morning, he was up and about. He strode purposefully to the Oval Office. It was locked. He had to go wandering through the corridors of the White House to find someone at last to open it.

The way in which he really dug his own pit in Watergate was the action of a man who believed he should be active. Again and again, he had only to lie low. Again and again, he was up in the morning, getting the key to the gardener's shed and digging another hole for himself. He was such a hungry doer that, to any true conservative, he was a dangerously radical man.

By far the most compelling reason for voting for Ronald Reagan -- certainly for a conservative -- is that he would use the presidency for taking a long nap. It might do America a great deal of good to have a Rip Van Winkle in the White House. I have an infinite trust in Gov. Reagan when he is fast asleep. All the evidence suggests that he is better at sleeping than any other candidate.

This is also what his proclaimed political philosophy is supposed to offer. Less government. Less doing. But, alas!, that is only on the surface. He is as much a doer as the rest. This is perhaps even more true of the kind of people whom it is believed he will bring into government. The cadres of impatient intellectuals who are lining up at the Hoover Institution, the American Enterprise Institute and the numerous burrows of political disaffection at Georgetown University are nail-biters who strain to get their hands on what even they call the levers of power. They are as insomniac as LBJ. Even a vast overdose of sleeping pills would not make them rest easy on their pillows.

They say that they would dismantle the overgrown apparatus of government. But the eagerness with which they would go about it leaves no doubt that their dismantling would be quite as active as mantling. They will simply create a different apparatus of government. To mantle is to put on a robe; to dismantle is to take a robe off. They have no intention of disrobing government.

They remind me of Talleyrand's answer when he was asked what was meant by nonintervention. He answered that "nonintervention is a metaphysical word, used in politics, which means the same as intervention." The only way to dismantle an overgrown government is simply not to use it. Let it atrophy. Do not even bother to fire government workers. You will just have to find them jobs elsewhere. Let them die off, and do not replace them. An organ which is not used becomes as dispensable as an appendix.

If this were what Ronald Reagan and his supporters meant, I would see high conservative reasons for voting for him and them. But this is not what they mean. They offer instead the worst of two worlds: men who disbelieve in government but are ceaselessly active in the exercise of government. They are not in the line of Calvin Coolidge, or of Robert Taft, who was a true conservative, or even of Eugene McCarthy, who ran a kind of troubador's campaign for the presidency. These are men who are hungry for the power and the doing of government.

The liberal critics of Jimmy Carter are not far wrong: he is the nearest to a conservative candidate that we have. Even the libertarian Ed Clark sounds like a maniac activist in comparison, as he offers such a frenzied use of government in order to dismantle it. The fact that Carter sleeps in an erect posture, and goes through the motions of wakefulness, ought not to blind the conservative to his real qualities.

There is no conservative supporter of Reagan today who would think it sensible to measure the presidency against a bishopric. It is often said that a presidential election is an opportunity for the nation to redefine itself. This is true. But it is in the nature of the presidency as an institution that it also is open to redefinition. A prime minister in a parliamentary system is tightly bound to the parliamentary process. He must choose his cabinet from very few known men and women who are prominent in his parliamentary party. But an American president is strikingly a free agent.

This is what makes a presidential election so tremendous an event. It is also what makes the institution so bewildering and often alarming to the outsider. It is part of what Macaulay meant when he wrote to an American friend: "Your Constitution is all sail and no anchor." Perhaps even more to the point, the fact that he is a free agent can be as much a source of weakness as of strength to a president, since really he has no reliable support. But what is extraordinary today is that all three candidates are basically promising the same kind of presidency awake and doing.

There is not one whom one can imagine dreaming of a bishopric, or even of a deanery. I offer only the serious thought: Reagan is the most radical activist of them all, and his appointees will be meddling clerics.