Ronald Reagan has attained a status he does not want. He is the least popular president at this point in his term of any White House occupant since Harry Truman. The mid-March Gallup Poll shows 46 percent approval of the way he is handling his job, 46 percent disapproval. That puts Reagan 4 points behind Jimmy Carter at a comparable date, and one point below where Jerry Ford, the unelected president who never recovered from his pardon of Richard Nixon, stood after 14 months in office.

The immediate cause of the public's unhappiness with Reagan is the recession, which has spread from autos, agriculture and housing into almost all sectors of the economy and most communities in America. The persistence of high interest rates in the face of the worst unemployment in 40 years has undercut public confidence in the bold and in some respects painful new economic program Reagan put in place last year. It is clouding his party's prospects in the mid-term election.

Reagan is further dogged by a degree of public uneasiness over his instincts and his steadiness in foreign affairs.

But at a deeper level of explanation, many scholars also see Reagan as only the latest in a line of victims to the intractability of policy problems and the impatience of public opinion. His plight raises again the question of whether the presidency has become "mission impossible" in this era of history.

That view has become almost conventional wisdom among many students of the office, some of whom have no real liking for Reagan's particular policies. In a 1980 revision of his classic study, "Presidential Power," Harvard political scientist Richard E. Neustadt said, "Our system now encounters two opposed conditions simultaneously. On the one hand, a president is still possessed of constitutional and statutory duties, with associated expectations, far in excess of his own assured capacity to carry through. On the other, congressional and public moods since Watergate, piled on electoral politics in recent years, drain all stability and certainty out of the terms on which a president once sought support from others whose authority or influence could reinforce his own. The gap between responsibility and capability grows wider."

Reagan sought to fill that gap with his voice. When he was asked, before the election, in an interview with The Washington Post, how he would achieve his goals, he said he hoped to build a closer relationship with Congress than Carter had enjoyed and believed--on the basis of his California experience--he could work successfully with the legislative branch no matter which party controlled it.

"I want to work with the Congress," he said, "but I also believe the president has another weapon. If they don't go along, you can do as Franklin Delano Roosevelt did, and take your case to the people . . . . As I said in California, they the legislators may not see the light but they feel the heat."

In 1981, Reagan did exactly that, and in a fashion that dazzled both the politicians and the people. He put his economic and defense program before Congress, lobbied directly with members for support, and, when the issue was in doubt, appealed on TV to the voters for help in moving their representatives. It worked--at least for a while.

But now Reagan has found, as his predecessors did, that popularity is short-lived. He is struggling, as they did, to protect his dwindling leadership capacity and avoid being overwhelmed by events.

Since last August, when the budget and tax plan that were at the heart of his first-year program were passed, Reagan has been increasingly on the defensive. High interest rates have thrown the economy into reverse. Congress, which seemed eager to do his bidding last year, has rejected his budget and is moving ahead without him to attempt to write its own. Key Republican legislators, who rallied near-unanimous support for his program in 1981, are telling him publicly that he is dangerously out of step with the times.

The world has proved to be full of vexations. The Soviets suppress the Solidarity movement in Poland, despite Reagan's pleas and threats. Cuba continues its finagling in Central America. A carefully arranged election in El Salvador produces the threat of a government distasteful to American policy makers. A European-bred nuclear disarmament movement jumps the Atlantic, takes root in the United States and pressures the president to offer concessions in negotiations with the Russians.

While the particulars vary from presidency to presidency, the pattern is familiar. In his 1976 book, "Organizing the Presidency," Stephen Hess of the Brookings Institution, a veteran of the Eisenhower and Nixon White House staffs, gave a description of a president's second year that sounds prescient when applied to Reagan.

"By the end of his first year," Hess wrote, "the president will have learned two important lessons: first, that the unexpected is likely to happen; second, that his plans are unlikely to work out as he had hoped."

"Presidents start to turn inward, some sooner than others . . . . Reading the morning newspapers becomes less satisfying. They bring bad news. They never seem to get their stories straight. Editorials and columns note only the things that go wrong. The president holds fewer news conferences. He looks for ways to go over the heads of the press corps, such as televised speeches . . . .

"Some members of his Cabinet, he feels, have 'gone native.' They badger him on behalf of their departments' clients . . . . There are now longer intervals between Cabinet meetings . . . . Time is running out on his first term. Things are not getting done. He begins to feel that if he wants action, he will have to initiate it himself--meaning through his own staff. The White House grows bigger . . . .

"The midterm congressional elections approach, and the president tries to restore his luster at the polls. He always fails. His party loses seats. The new Congress is less receptive to the president's wishes . . . . "

Not all of this has yet happened to Ronald Reagan, but the symptoms are there, and so is the psychology. "I've come to the conclusion," Reagan told reporters last December, only half-kidding, "that there is a worldwide plot to make my job more difficult almost any day I go to the office." In a conversation with NBC's Tom Brokaw, he added that "preparing the 1983 budget, plus the roof falling in on some of these international affairs, there are days that all seem like Monday."

Many scholars think that we are in an era of Mondays, and that is why no president since Eisenhower has gone eight years in the job.

The United States has lost its unrivaled position in the international economic and military order. That is a fact of enormous import, when it comes to the performance gap of presidents.

"My generation," said the University of Virginia's James Cesar, who is 36, "had its expectations formed in the 25 glorious years of unchecked economic growth from 1940 to 1965. It was a period when we were dominant in the world. Both those conditions were aberrations in world history, but we took them as the norm. And it has led to unreasonable expectations."

America's economic vulnerability was dramatized by the 1973 oil embargo, the after-shocks of which on prices and productivity are still being felt here. In a real sense, each of the last four presidents has struggled to cushion the country against the effects of the oil-price jolt; and all have paid a price for their failure.

The end of America's military-diplomatic dominion was dramatized in Vietnam and certified in Iran. The last five presidents have struggled to find a basis for asserting American power and defending American interests in the world, without risking another military defeat or diplomatic debacle. All have paid a price for their failure.

Given this history, there is every reason to wonder why Americans hold such high hopes for each new president--and why they are so quickly disillusioned. The answer to the first question, political scientists suggest, has much to do with the way in which people campaign for the office.

Running for president has become an increasingly prolonged and personal enterprise. Aspirants are out seeking support for two, three, four or--in Reagan's case--six years before the election. For all but the last two or three months, they are on their own; until actually nominated, they have no party machinery on which they can rely, and even then, they must depend largely on their own wits and staffs.

During that prolonged period of competition, each must claim to have unique qualities that guarantee success, which their rivals, and especially the incumbent, do not possess. Carter said he would succeed where Ford had failed; Reagan said he could do what Carter had not done; and if Reagan runs again, some Democrat will certainly say he can triumph over the problems that frustrated Reagan.

Once in office, the tendency is for presidents to try to strike fast, before their opportunity fades. Harry McPherson, a Lyndon Johnson aide, quoted his mentor as saying, "You've got to give it all you can that first year. Doesn't matter what kind of majority you come in with. You've got just one year when they treat you right . . . ."

But that first year is a learning period for the president and his aides, who are probably more skilled in campaigning than in governing. "It is not surprising," Hess of Brookings writes, "that some of the greatest presidential disasters . . . have come in the immediate afterglow of election victories. Indeed, the bigger the victory, it seems, the greater opportunity for disaster."

In his 1976 book, he cited Kennedy's Bay of Pigs decision and Johnson's 1965 decision to escalate the Vietnam war. Now, one might add Ford's pardon of Nixon and his ill-timed WIN button campaign against inflation, and Carter's equally hasty plunge into an economic stimulus program and a poorly conceived energy plan.

Whether historians will note similar misjudgments on Reagan's part is conjectural. His aides have conceded one huge blooper in the first months--the proposal to trim Social Security benefits--but they would not yet admit that the landmark budget-and-tax bill was a fundamental mistake.

Yet the criticism of Reagan is abundant, as it was for previous presidents at this point in their terms. Most scholars of the presidency argue that this has as much to do with the mass media in this country as it does with the presidents they cover.

Austin Ranney of American Enterprise Institute, a former president of the American Political Science Association and a Democratic Party activist, observed last week that "the media in general, and TV in particular, make it tougher for presidents to succeed. They accelerate political consciousness and feed an impatience for quick results, no matter how complex the problems. They want things solved in 60 minutes--less commercials.

"If the Civil War had been fought in the television age," Ranney said, "I have no doubt there would be an independent Confederate States of America today, because that was a mismanaged, bungled operation by the Union almost until the end."

In a similar vein, the University of Virginia's Cesar said that Abraham Lincoln, who put down some incipient challenges to renomination in 1864, might well have suffered LBJ's 1968 fate if he had had to contend, as Johnson did, with the modern mass media.

Nor is this view confined to the academics. Godfrey Hodgson, the British journalist, says in his 1980 book, "All Things to All Men: The False Promise of the Modern American Presidency," that fundamentally, "the modern media created the modern presidency," so closely are the two linked. Televison, Hodgson said, is "a machine able to project personality and policy alike instantaneously into every living room in the country, satisfying every politician's heart's desire" and giving presidents an unrivaled tool for shaping public opinion. But, he said, "with this electronic Mephistopheles, presidents have made a Faustian deal," because the same instrument that elevates them so often has turned out to be the engine of their destruction.

None of these problems came as a surprise to Reagan or his associates. They were outlined in advance, among other places, in a book published during the Reagan transition by the Institute of Contemporary Studies, a California "think tank" with close links to Reagan and presidential counselor Edwin Meese III.

In the introduction to that volume, University of California-Berkeley Professor Arnold J. Meltsner addressed Reagan directly. "Some say the president can't govern because there is: a lack of public consensus or trust; a nation that confuses its powers with your more limited power; a decline in political parties; a rise in single-interest groups; a fragmented Congress with aggressive members; and personality- and pathology-oriented media; a policy-making judiciary; a permanent and often independent bureaucracy; and a chronic and often unanticipated policy agenda."

"But," Meltsner said, "you can govern." And he offered Reagan five pages of compact advice, emphasizing the need for a president to set his own "short list" of goals, to organize his office to suit his own needs and constantly to nurture coalition support for his own objectives.

Last week, Meltsner said he thought Reagan had followed that advice well in the first year and the success he enjoyed "confirmed my notion that a skillful president can still assemble majorities, despite the fact that the systemic problems we mentioned are still there."

Meltsner said he thought Reagan is in trouble now because he has been "too consistent" and has failed to endorse the budget compromise that might ease interest rates and shorten the recession. He blamed that on a tendency for those in the White House "to be too damn introverted" and to cut themselves off from "the expertise in the bureaucracy" and the advice of allies in Congress and the GOP.

But, he said, "the president still has a constituency in the country, and I wouldn't count him out."

A very different view is taken by Lloyd N. Cutler, the Washington attorney who was counsel to President Carter. While he was still in the White House, Cutler wrote an influential article in Foreign Affairs magazine, arguing that no president can succeed until the American government structure is revised to incorporate at least some of the elements of a parliamentary system, in which there is a degree of assurance that the leader of government can put his program into place at the outset of his term.

Cutler said this week that he finds "nothing to be happy about" in Reagan's difficulties. Reagan's plight, Cutler said, only confirms his belief that "no president can match the expectations that are created, because the president does not hold the power to govern; no one does." Reagan's first-year success, in Cutler's view, was a fluke, and has added to the problem by confirming the exaggerated expectations that were fostered by Reagan's own campaign rhetoric and the press buildup of those early victories.

Harvard's Neustadt dissents. Like Meltsner, he sees Reagan as a man who demonstrated a remarkable skill in congressional politics, management of the White House and use of the mass media in his first year. The problem, says Neustadt, is simply that "there was a hole at the bottom of his policy; the numbers didn't add up." If they had, he says, Reagan "might still be dazzling us." And even now, there may be time for him to cut a budget deal with Congress that will save him.

At the White House, where few officials have the leisure or detachment to analyze the lessons of the first 14 months, the view is that Reagan will recover politically when the economy revives, just as he came back from a slump in California polls stemming from the misguided presidential bid he made 15 months into his governorship.

His personal credibility is still intact, officials say; he has suffered no self-inflicted wound remotely comparable to Nixon's "Saturday night massacre"; Ford's pardon of Nixon; or Carter's Camp David-Cabinet purge fiasco. Neither has Reagan sunk into a "bunker mentality" of thinking he is surrounded by enemies.

Indeed, they note, Reagan has yet to be reversed on any major policy position on the floor of the House or Senate. The problem is as simple--or complex--as the economy.

They may be right. But the bad news most scholars of the presidency read in the polls is that Reagan at this point is being propelled down the same path by many of the same forces that pushed his predecessors into frustration and unwanted early retirement.