WHAT MANY perceive as a groundswell of conservatism in the United States - a "New Right," as it has been called - may instead be only an expression of extreme dissatisfaction with the federal government, a Washington Post national poll suggests.

There may be no "New Right" at all. On issue after issue, Americans appear to have hardly shifted their positions one way or the other over the last 10 years.

At the same time, however, disenchantment with government performance, once expressed mainly by ideologues of the right, has risen dramatically in all groups: those who consider themselves liberal, moderate or conservative.

In short, until they feel the government has shaped up, it appears, many Americans of all persuasions have adopted a "conservative mood" - but nor conservative positions on issues.

The Post's findings generally coincide with a statement by a second-term Georgia Democratic congressman, Elliott H. Levitas, who has come out strongly against government programs that are often considered liberal, such as a bill to create a consumer protection agency earlier this month.

"We have not seen an abandonment of the ideals of liberalism," Levitas says. "People are just as concerned about ideals and goals today as they were 20 or 30 or 40 years ago.

What they have become jaded and cynical about is the ability of government to meet those goals."

One thrust of The Post's findings is to cast doubt on the assertion by right-wing groups that the time is ripe for conservative candidates to unseat liberal or moderate incumbents of both parties in this year's House and Senate elections.

John Sears, who managed Ronald Regan's campaign for president in 1976, said in a telephone interview that he agrees with that conclusion. Despite his ties to one of the most conservative leaders in the country, Sears said he sees no signs that American voters are about to accept candidates who appear committed to an ideology.

Citing a far right-wing challenge to the third-ranking Republican in the House leadership, John B. Anderson of Illinois, Sears said, "if Anderson loses, it will be more the fact that he is not putting on a good campaign than his opponents's political philosophy that accounts for it." Social Welfare Views Stable

THE POSTS poll was conducted at the end of january, with a random sample of 1,519 adult Americans interviewed by telephone. Results of the interviews were compared with responses to similar questions that have been asked by national opinion researchers over the past 40 years.

While it is impossible to extract the full diversity and complexity of the public's attitudes from these polls, certain clear patterns emerge. For example, according to surveys conducted by the University of Michigan, the number of Americans who said they did not trust the federal government to do what is right more than doubled from 1966 to 1976, from 30 per cent to 63 per cent.

The number who said the government wasted their tax dollars rose from approximately half to three-quarters of the population, and those who said the federal government was getting too powerful climbed from 42 to 68 per cent.

At the same time, opinion on government objectives has remained virtually stable. On issues ranging from social welfare to abortion to national health insurance to law and order, the proportion of "liberal" and "conservative" responses has essentially stayed the same.

Attitudes on social welfare issues have been perhaps the most stable. Indeed, since the New Deal, Americans have supported government policies to promote full employment, housing, medical care and other so-called liberal programs by steady ratios of 2 to 1. The Post poll shows that sentiment enduring.

Along with it, however, has existed a resistance to innovative policy departure. Thus, while 55 per cent of the respondents told Post interviewers they agreed that the government should substantially reduce the income gap between rich and poor, 58 per cent said they were opposed to substituting a guaranteed-income plan for the current welfare system - a level of opposition that falls right in line with that found in earlier polls.

When faced with the choice of expanding social programs or cutting government spending to balance the budget, the American public has been almost equally divided in recent years. In 1975, the Gallup Organization found 42 per cent for balancing the budget, 46 per cent for more social programs. In 1976, a CBS-New York Times poll found a similar 43 to 48 per cent split. The latest figures from The Post poll are virtually identical, 43 to 47 per cent.

On racial issues, the polls have shown a marked acceptance of principles of equality since World War II. As in other matters, however, the majority of people are reluctant to support government programs aimed at enforcing racial equality.

In 1976, nearly 85 per cent of the respondents in a poll conducted by the National Opinion Research Center in Chicago said they thought black and white students should go to same, rather than separate, schools, double the number holding the view in a 1942 poll by the same organization. But in the 1976 poll, only one-third of the respondents said they favored government implementation of school intergration. More Liberal Life Styles

IN ONLY one area do The Post's poll and other polls suggest significant change over the last decade, and that is in a liberal direction on what might be called life-style questions. On how severe penalties should be for the use of marijuana, on the right of newsstands to sell pornography, on the role of women in society and on several other such issues there has been unmistakable movement toward a more tolerant or "liberl" point on view.

But such changes are clearly the exception. On the whole, the stability of ideological positions is well reflected in the way Americans describe themselves.

Between the early 1960s and 1970, the number of people calling themselves conservative increased sharply, in all probability due to the growing importance in that period of social and racial issues, on which the public holds faily conservative views.

Since 1970, however, the proportions calling themselves conservative, moderate or liberal have deviated little from year to year. Indeed, the tiny fluctuations that do appear may be due simply to the margin of error or slightly differing question wording associated with each survey.

Gary Orren, an associate professor of politics and government at Harvard University who is assisting The Post in its polling operation, says the distinctions between traditional conservatism and the new "conservative mood" are vital politically.

"Both create opposition to government action," he notes. "The older, ideological variety of antigovernment conservatism, however, encourages political candidates who are ideologues. It invites issue politics, in which battles revolve around public debate over specific policy.

"The new conservative mood discourages such ideological contests. It provides fertile ground for more centrist candidate who downplay substantive issues and call attention to the need for competence, better management and trustworthiness in government."