In New Mexico, Democratic Rep. William B. Richardson prepared for debate on President Reagan's tax-revision plan by sending out 100,000 questionnaires on the issue. But in a series of seven town meetings across his northwest New Mexico district the other day, only two of his constituents even mentioned tax reform, both expressing concern about the proposed elimination of mortgage deductions for second homes.

In Iowa, Republican Sen. Charles E. Grassley noted with pride that he won passage of an amendment cutting the president's defense budget by $17 billion next year. "Why not $117 billion?" asked a grim-faced farmer who blames military spending for contributing to a federal deficit whose consequences threaten his livelihood.

In Illinois, Democratic Rep. Lane A. Evans found that farmers who not long ago supported the administration in opposing protectionist legislation are now having second thoughts. With bad times on the farm, many have taken second jobs in factories and fear that those jobs are vulnerable to foreign competition, a "double whammy," as Evans put it.

Several times since Reagan took office in 1981, The Washington Post has traveled with lawmakers as they visited with constituents to assess the political pressures they feel and to gauge public attitudes toward Reagan administration initiatives. Reporters did so again over the last three weeks, spending a day or more with 13 House and Senate members of both parties in all regions of the country.

Their findings suggest that the "morning-again-in-America" mood of Reagan's reelection campaign last year has lost some of its glow, darkened by the reality of federal budget deficits, failing farms and factories at home, trade competition from abroad and a host of other worries ranging from toxic pollution to health care costs.

At the same time, though, for most Americans this is a time of relative peace and prosperity. For many, deficits remain an abstraction, albeit a worrisome one, and there is no consensus on how specifically to solve the problem. Moreover, with no international conflagration threatening world peace, and a U.S.-Soviet summit in the offing, concern over international affairs has subsided.

In the town meetings and club gatherings and walking tours where lawmakers meet the public, voters frequently express foreboding about the future. But, except in areas where budget and trade deficits are seen as an immediate threat to jobs, none of the major issues before Congress has reached the political crisis point that demands action.

Reagan remains personally popular, but that popularity does not necessarily extend to support for his specific programs, a dichotomy originally noted after the president's first triumphant year in office. This summer, many voters spoke of Reagan -- or failed to mention him -- in ways suggesting that he has slipped as a driving force in day-to-day shaping of public policy.

Even more than before, Reagan's priorities seem to conflict with those of lawmakers and their constituents. The conflict occurs on issues ranging from tax reform to defense and trade. While the president had strong public backing during his almost single-minded post-election push to cut taxes and non-defense spending in 1981, Americans appear to be paying scant attention to the more cluttered, less compelling agenda of Reagan's second term.

The priorities of Americans and their legislators also vary sharply from district to district, state to state, and they often conflict. With no overarching national consensus, conflict and drift, not decisive action, appear to be most likely as Congress returns to wrap up work for the year -- the House on Wednesday, the Senate next Monday.

There is potential for conflict between the White House and Congress on numerous issues, but trade is emerging as a major source of disagreement. Members from states as varied as Georgia and Illinois heard pleas from constituents during this recess to curb imports in defiance of the president's free-trade policies.

Even at a nursing home in Monmouth, Ill., the questions quickly turned from health care to trade. One senior citizen asked Rep. Evans about the possibility of "taxing those industrial robots -- how many American cars do they buy?" Especially for Democrats hungry for a good campaign issue, protectionism was taking on an aura of patriotism. "This country was built on protectionism," Rep. Wyche Fowler Jr.(D-Ga.) told a group of Atlanta business leaders.

In farm-belt states such as Iowa, there is near-rebellion, even among Republicans, over Reagan's farm, fiscal and trade policies.

Farmers complain that Washington, including Reagan, has forgotten them. One asked Grassley if the White House was sensitive to the plight of the family farmer. Republican Grassley furrowed his brow and then responded, "No, really, I don't think so."

Nearly everywhere, the president's push to overhaul the tax code has activated special-interest lobbies opposed to specific changes. But it has failed to capture the imagination, or the support, of average taxpayers. Most people appear confused, skeptical and even cynical about whether tax revision will benefit them personally or the country as a whole. Many saw no sense in rewriting the tax code unless the effort yields more revenue to help combat deficits.

"If it [the tax code] is simplified, how long are you folks going to quit messin' with it?" Rep. Martin Frost (D-Tex.) was asked. "Not long," Frost responded. Said Ralph Deslauriers, a Vermont ski resort executive who served on Reagan's reelection committee last year: "All this fiddling around with tax policy -- do something or forget it. I think it's idealistic and simplistic. We need more tax dollars, not less."

For all the taxpayer griping about complexities and unfairness of the tax code, hardly anyone mentioned reform as a leading priority. Even Sen. Bob Packwood (R-Ore.), chairman of the Senate Finance Committee, which will handle the legislation, heard almost no mention of it at home. Defense Abuses Resented

Opposition continues to mount to Reagan's defense buildup, sparked by outrage over what many regard as excessive charges by defense contractors and by concern over the impact of ever-higher defense spending on budget deficits.

"Even in rural areas, even among conservative Republicans, people are pushing for deeper defense cuts," said Rep. Alan D. Wheat (D-Mo.). Deficits are one reason; fair play is another, perhaps even more compelling, factor. At a town hall meeting in Sugar Creek, Mo., Wheat's constituents boiled over at the notion that some of the defense contractors that have overcharged the Pentagon have paid no taxes. "They got different laws for them and us," said one, suggesting "a lot of time in Leavenworth" for the next violator.

The end of support for the military buildup may, ironically, have come at the cost of a toilet-seat cover that Lockheed sold to the Navy for $640. "If I saw that our money was being spent wisely it would be one thing, but when you read how much they're spending on hammers and toilet seats you can't help but wonder what they're blowing on the really big things," Mark Muller, a Mebane, N.C. resident, told Rep. Howard Coble (R-N.C.).

Similar sentiments on defense were heard all around the country, but -- in part because of the uneven distribution of prosperity -- there were also sharp contrasts in voter concerns, even within seemingly homogeneous regions.

A reporter accompanying two House Democrats from Midwestern districts 200 miles apart, Reps. Thomas E. Petri (R-Wis.) and Lane Evans (D-Ill.), found Evans and his constituents absorbed with job-related trade issues, while Petri and his people are preoccupied with budget deficits and cared little about trade problems. Evan's district is especially export-sensitive and less diversified than Petri's.

Similarly, Packwood was besieged with the abortion issue; Grassley hears only of farm problems; Sen. Patrick J. Leahy (D-Vt.) is asked constantly about arms control and other peace-related issues.

The one common ground shared by Reagan, Congress and the country as a whole is concern over soaring budget deficits. "People are not going to learn to love the deficit and forget about it," said Rep. Marge Roukema (R-N.J.), who, like many of the lawmakers, is asked most often about deficits.

An oil-lease broker who is on the verge of going out of business told Sen. Don Nickles (R-Okla.): "The government don't care about us. If they did, they wouldn't have us billions of dollars in debt."

In farm states especially, people draw a direct connection between deficits and their own survival, largely because of the impact of deficits on interest rates and the dollar. Elsewhere, the connection is murkier, although most people seem to regard the deficit as the government's number one problem -- a threat for the future if not the present, a burden for their children and grandchildren if not themselves.

But there appears to be no clear-cut consensus on what to do about the problem, aside from generalized proposals for across-the-board sacrifice, including more restraint in defense spending. While tax increases do not appear to be the political taboo that Reagan and some Democrats suggest, there is no clamor to raise taxes either, except possibly in connection with tax reform.

A town meeting in Sante Fe, N.M., illustrated the problem. When a constituent suggested a balanced plan of tax increases and spending cuts to eliminate the deficit in five years, Richardson said, "Heck, everybody's for that," and then took a vote on the idea. It was rejected, 2 to 1, because people feared the results might be too drastic.

At other meetings in New Mexico, there were pleas for even more spending: more medical assistance, highway aid, water projects, school aid, legal services. "These deficits are probably limiting what we can get from Washington . . . but we really need some way so that the government would take over some of our medical costs," said Wanona Maestas in Jemez Springs.

People in areas where the economy has rebounded, which includes most of the country, tend to share Reagan's upbeat view of America-on-the-mend. But there are vast exceptions, including the nation's industrial and agricultural heartland, where the present is bleak and the future looks even bleaker.

Almost everywhere are varying degrees of foreboding about the future, especially about the country's ability to hold onto its jobs, standard of living and national pride in the face of foreign competition.

"I have been in business for 26 years and I have never seen the business climate as poor as it is right now. There's very little that can be considered in good shape long-term," said Joseph Cox, president of a Claremont, Okla., manufacturing company. Said Arthur P. Smith, a retired insurance agent who came to hear Roukema at the Ridgewood Rotary Club: "I'm going to get through this all right, but I'm worried about my grandchildren."

In most areas, the president can still arouse support for his broad thematic approaches, including curbing the growth of government. "Basically they [New Yorkers] are happy with his leadership," said Sen. Alfonse M. D'Amato (R-N.Y.). "People come up to me and say we expect you to support the president." And an apparent disinterest in foreign policy, except among those who follow such matters closely, gives at least a superficial impression of satisfaction with Reagan's handling of world problems. Reagan Less of a Force ---

But, in addition to opposition to many of his specific programs, there are suggestions in states from Texas to New Jersey that Reagan is less of a dynamic force in policy debates than he once was -- reigning more than ruling.

In many constituent encounters with lawmakers, Reagan's name was rarely invoked. People often spoke impersonally of the "White House" rather than the president by name. This may stem from the cancer surgery and subsequent vacation that has removed the president from daily view over the last couple of months. But it also raised questions about Reagan's ability to marshal support for his legislative program over the next 3 1/2 years, a problem aggravated by his lame-duck status.

Texas Rep. Frost found a change in Reagan's role in connection with tax revision in his Dallas-area district, which includes exclusive suburbs in addition to working-class areas, and a constituency of blacks and Hispanics as well as whites.

"There is nobody who stands up and says, 'By God, I'm for that [tax revision] bill. There's also nobody who says, 'Look, we've got to support the president on this one.' In my district, that's a real change," said Frost, who has been accustomed to hearing appeals to "win one for the Gipper," especially from his upper-income constituents.

Congress still tends to get most of the blame for deficits, with few paying much heed to its efforts to impose curbs on deficit growth. But there is disappointment as well over Reagan's handling of the issue, an impression that he may not have a grip on the problem.

In New Jersey, Thomas Craig, a coffee company sales manager from Waldwick, who voted for Reagan because he thought Democrat Walter Mondale was a "wimp," is disappointed. "Reagan is living in a dream world," said Craig. "He thinks we're going to grow out of this deficit."

Smith, the retired New Jersey insurance agent, continued to support Reagan but with some misgivings: "I feel he's a good leader, but we have to urge him to get with it."

Except for some questions about South Africa, especially from black and liberal groups, there was a dearth of interest in foreign policy issues. Some lawmakers believe that is due to the absence of an all-alarms crisis such as the Soviet downing of the Korean airliner that rocked people out of their late-summer lethargy two years ago.

But others suggested an increasing introspection on the part of many Americans, prompted both by domestic problems and by concern over pressures from abroad, including immigration as well as trade competition. Wheat, for one, has been surprised by the hostile questions he gets from his Kansas City constituents on foreign aid and immigration. "The country seems to be drawing inward," he said.