The president was bemused. Painfully wise in the ways of Washington, his days of power waning, and bearing the scars of massive public rejection (no eye ever had sunk lower in the opinion polls), he took sardonic pleasure in thinking of what lay ahead for his successor -- who had, of course, promised to make it all better. "He'll sit here," the president said to an Oval Office visitor shortly before the inaugural ceremonies were to begin, "and he'll say, 'Do this! Do that!' And nothing will happen !"

That was Harry Truman speaking of Dwight Eisenhower, but it could have been any of those who followed him into the White House, of Gerald Ford referring to Jimmy Carter, or, on this latest inaugural day, Carter of Ronald Reagan. "Poor Ike," Truman had said, with a tinge of mock sorrow, "it won't be a bit like the Army.He'll find it very frustrating." Poor Ronnie, Jimmy can now say, with equal solicitousness toward a triumphant political opponent, it won't work at all the way he thinks it will.

When it comes to new presidents seeking to make Washington conform to their wishes, the words of F. Scott Fitzgerald are applicable. So we beat on, he reminds us, boats against the current, drawn back ceaselessly into the past. And so we begin again, the air filled with fresh presidential pledges to make more shining this symbolic capital on a hill, as the new chief executive might say, even as the old rhetorical promises faintly echo off the marble walls.

Now it becomes Ronald Reagan's turn. Like a character out of one of his Western melodramas, he brings his white hat and cowboy boots into the weary East of Washington, ready to ride herd on the federal establishment, reign in its excesses and redeem his promises. He exudes optimism, says he has no fears of the future, rejects the counsels of gloom long heard in the capital and summons the nation to a new age of great achievements.

As the imperious old general, Douglas MacArthur, told the energetic new young president, John Kennedy, not long after the inauguration exactly 20 years ago, "The chickens are coming home to roost. And you're in charge of the chicken coop now."

Welcome to Washington, Mr. President, the city is yours -- for a day. The country looks forward to your good works -- for a time, at least. The people patiently await the fulfillment of your promises -- for the moment, anyway.

In recent years, no promise has been made more fervently than to change the way Washington works -- and, as presidents come and go, none seems more difficult to achieve. That is not to inject a tired air of cynicism on this day of national celebration, when hope becomes the hallmark of the land and all things momentarily seem possible.

But the occasion calls for at least some realism about the facts and fictions of Washington and about what our increasingly swift succession of presidents can do about them. Nothing could be more illustrative than the example of the two men, the 39th and 40th presidents of the United States, who will occupy center stage on the Capitol Hill inaugural platform at high noon today.

The fascination is not how these political rivals differ in their approach to governing, but how alike they are. Yes, that's right, alike. Seldom has history, or fate, offered American voters, back to back, such similiar choices.

Personal and geographical differences aside, the political appeal of both Carter and Reagan was strikingly alike. They offered themselves as outsiders intent on setting right the well-known horrors of Washington. Each promised dramatic reforms of the way government functions, and each time the people believed them -- or enough did to place them in power. They were politically pure; no taint of wicked Washington sullied them. And they laid before the public specific plans of action.

Candidate Carter, 1976: "I have personally seen the almost total impossibility of administering the uncoordinated, conflicting, and wasteful hodgepodge of programs and laws that result from the present disorganized condition of our federal government."

He was going to start fresh -- remember zero-based budgeting? -- and trim the waste and fat from the ranks of those federal workers, the subject of so much political caricature. He was going to lead a "thorough and massive reorganization of the federal bureaucracy."

Candidate Reagan, 1980: "Our federal government is overgrown and overweight. Indeed, it is time for our government to go on a diet. Therefore, my first act as Chief Executive will be to impose an immediate and thorough freeze on federal hiring. [Carter already has imposed one]. Then, we are going to . . . conduct a detailed review of every department, bureau and agency that lives by federal appropriation." He promises to eliminate governmental "confusion and waste" and issue the direct presidential order: "Any program that represents a waste of their [the public's] money -- a theft from their pocketbook -- must have that waste eliminated or the program must go -- by executive order where possible, by congressional action where necessary."

In each case, voters liked what they heard. First, they rewarded Carter; then, they punished him when his prescription proved less beneficial than advertised. Now they have crowned Reagan and await his miracles -- but hold their weapon of retribution at the polls in reserve.

Which all precisely encompasses the problem: the politicians keep promising easy solutions, when there are none; they keep placing collective blame on bureaucratic Washington, when the real culprits lie closer to home. And the public, which keeps hoping for the promised wonders to occur, while demanding more and more of the government it condemns, winds up being even more disgruntled than the last time its added benefits fail to materialize.

Whack! Another politician -- or another president -- bites the dust.

Reagan's record of political promises is especially noteworthy when set against the reality of the Washington he now faces. For far longer than Carter, he has been running against the central government and Washington. It has been his theme for almost a generation. He takes a laissez-faire approach -- a belief in voluntarism, in private enterprise, in blue ribbon commissions and task force reports. Therein lies his path to "getting government off our backs."

If he has a clearly held governmental philosophy, it would appear to be a Jeffersonian one: government governs best that governs least. Not long after he became governor of California 14 years ago, he remarked, somewhat plaintively, "I've often wondered why there are so many laws that have to be passed." He quickly added an after-thought: "Maybe we should see how many we can do away with."

The problem is, at this period of American life, that simply won't happen. All political promises notwithstanding, the one certainty about administering power from Washington today is there will be more, not less, govenment in our lives. The real question is not the size of government but how effectively it functions.

Of all the myths about Washington and the federal government, perhaps the greatest involves the canard about the "bloated bureaucracy" being the source of woe. It's true the numbers of federal employes in Washington have risen, but barely. But in terms of the total population the number of federal employes has grown hardly at all.

Take the situation Carter confronted when he came to power four years ago this day. The United States government was then employing 2,874,000 people. Lots, to be sure. But, in the 26-year period up to then, a time when the United States assumed preeminent worldwide responsibilities, fought two hot wars (and a cold one), became the military shield for western civilization, added governmental benefits that affected the lives of all Americans, and saw the demands on government increase extraordinarily, the figures told a dramatically different story. Over that span of a generation, the proportion of federal workers among every thousand persons employed in the United States had risen from only 13 to 14 -- and that latter figure had remained exactly the same for 20 years.

The startling growth in American government came elsewhere. Again beginning in 1950 and ending with 1976, the number of state and local employes had tripled, from 4,285,000 to 11,755,000. Bureaucratic growth was occurring not so much in far-off Washington but in the governments closest to the people at home, who continued to demand more and more services. The representatives they sent to Washington responded by enacting new legislation establishing programs and agencies, creating bureaucracies at home to deal with the federal largesse.

It is easy to blame the bureaucracy but convenient to overlook why -- and how -- it exists. In a pluralistic society of 226 million diverse people, government reacts to disparate demands.

It attempts to redress society's ills and attend to the needs of the sick people, poor people, disabled people, uneducated people; to ease the ravages of a recession; to help a failing industry (bailing out Chrysler, at a cost of billions of dollars) or a threatened one (placing higher import levies on foreign goods); to answer the call for better public health and safety; to meet the cries for stronger national defense to pay the price in benefits for those who fought in America's wars. Thus the new laws pass, the new appropriations flow, the new bureaucracies multiply.

And thus, over the decades, the cost of the federal government rises with inexorable, geometric progression no matter who sits in the Oval Office, and despite all promises to reverse the process. Jimmy Carter's first budget of $500 billion was five times greater than John Kennedy's, 50 times that of Franklin Roosevelt's, 500 that of Woodrow Wilson's.

Now Reagan must grapple with those facts and try to balance the conflicting appeals to him from so many groups. Even more difficult, he must resolve the contradictions in his own promises to balance the budget, slash taxes, cut the federal work force and yet somehow drastically increase defense spending and still not eliminate vital public services and programs.

A curious paradox places Jimmy Carter and Ronald Reagan together on the inaugural platform today. Carter came to power in part because the American people, who grew up believing in the mystical powers of their presidents, finally came to fear the chief executives had become too strong. Reagan assumes his mantle in part because the same people think the presidency has become too weak.

In less than a decade, we have reacted to the excesses of the powers of the supposedly imperial presidency of the Lyndon Johnson-Richard Nixon Vietnam-Watergate era and now the seemingly impotent presidency of the Carter years.

He all-wise, all-powerful presidents of the past never existed, of course, except in legend. American presidents always have had limitations on them.

No matter how great their desires or bold their purpose they all have been captives of the forces of their times, both institutional and historic. They can promise a mass transportation policy but fail to make the railroads run on time, they can declare war on poverty (or Vietnam) but never see victory, they can hail the dawning of a new age of environmental purity and see the clouds of pollution still darkening the horizon.

Recent presidential experience has led to new expressions of concern, academic and popular, about the forces that control presidents: their authority with the public has eroded, they have witnessed a resurgence of Congress intent on recapturing lost powers, they increasingly confront an immovable bureaucracy, they must battle an evermore entrenched and formidably organized group of special interests -- so go the arguments about the current decline of presidential power.

Four years ago, an outgoing Republican passed on some thoughts about the experience of governing in Washington to his Democratic successor. They remain as fresh today as then.

The United States government, he said, is like a peat bog. When you stand in one place you can make an impression, and the longer you stand there, the deeper the mark. But when you leave, the impression will disappear completely unless someone immediately steps in your place. Even then, it is hard to find any footprints on the permanent peat bog of government.

You hope, he went on, your service in government is not like that. You hope it's not like building a road through the jungle where four years later a stranger can't even tell a road was there.

Ronald Reagan rejects these stories of past problems and present litanies of structural flaws in the office of the presidency. "Our leaders seem to be saying that America's time of greatness is past," he said in his campaign, "that Americans have become self-indulgent, that our country was built on cheap energy and abundant natural resources which are no longer available. These are the arguments of despair." r

He takes office today with one more promise, and it is the most important of all -- that a president, sure of his goals, confident of his approach, certain of his exercise of powers still can have a profound effect on the destinies of the nation. Even in these difficult times, in this normally most cynical national capital, he has nothing but well-wishers as he begins to carve out his path through the Washington jungle.