Sen. Dale Bumpers flipped over a letter received by one of his Arkansas constituents. It was from Ronald Reagan.

The president was asking for campaign contributions to defeat what he called the "liberal Democratic majority" in the House of Representatives. The opening salvo in next year's critical mid-term elections was being sounded.

Bumpers and the rest of the Democrats in Congress are well aware of what they face next year. The Republicans are better organized, better financed, and better at using the computer technology that enables them to target groups, reach mass audiences, raise funds and generate powerful grass-roots forces.

The Democrats know, all too well, the fervor of the right-wing organizations pitted against them, and take a form of masochistic solace in hoping the zealots will be so vicious it will destroy them. Most of all, they know they face a more difficult problem.

"People think that 1980 was some kind of wild aberration that's not likely to ever be repeated again, and in one sense it was," Bumpers says. "That is, it all seemed to come together at one time. But you have to understand that this conservative tide in this country about government spending and government deficits and government waste and inflation really began back with Richard Nixon in 1968 to one extend or another. And you can't say that Jimmy Carter was an interlude because Jimmy Carter ran on precisely the same platform that Ronald Reagan did -- and promised the same thing and delivered nothing.

"What happened in this country -- and I know you've heard this before -- the New Deal and the Fair Deal and all those things really worked almost too well. Now it's kind of 'pull-up-the-ladder-Jack-I'm-aboard.' So many people have gotten on board that they're not quite as sensitive. They forget those people who are still reaching for the first rung of the ladder. It's not very trendy right now to say that you're sensitive to the plight of the poor folks and the people who still haven't made it."

Looking to the past, however glorious, offers small comfort for the Democrats now. Their problem is charting the future. Then, more difficulty, they must agree on how to get there.

The process already has begun.

Three areas are vital, and none of them easy. They must rebuild and regenerate the party structure that has fallen into such disrepair over the long years of lulling success; and they must bridge the widening gaps of sectionalism that further threaten to tear apart the party.

They must find common ground -- and a common theme -- that will unite them for the different political realities of the closing years pf this century.

Above all, they must pay greater attention to the changing national demographics that spell out a population shift of profound political and economic consequences.

The Southwest and the West form the great political battleground of the future. It is there the Democratic fate will be decided. On that, virtually everyone agrees.

Lane Kirkland, head of the AFL-CIO and thus of America's organized labor movement, will point to the West as the place where the unions intend to exercise much of their political muscle.

Development of energy sources in the Rocky Mountain states, with the inevitable population and economic boom that seem destined to occur rapidly this decade, already is getting sharp attention.

As one of Kirkland's operatives says, "The idea of the new liberal South is baloney. It's a new South, but it's still ultra-conservative, and it's a Republican South. That probably would have been very clear if it hadn't been for the fluke of Jimmy Carter. I happen to think the political ground in the next decade is out in the West. That's where you find all these big questions about energy and resources and land and people. There are going to be major new industrial areas out there, and what happens to them? We have started talking about it.

"Lane has made it very clear to a lot of different folks -- public officials, industry officials, political people, our people, the whole gamut -- that we're convinced that's where the real fight's going to be. And we're making it clear that it's not just whether the synfuels plant is going to be built by union labor that's our interest. If they think that's all we're interested in, they better forget it.

"We're interested in the whole schmeer: the hospitals, the transportation, the environment, the type of city it's going to be. We're not just interested in building sites. Our interests go all the way: what kind of city council they're going to have, what sort of people are going to be employes, what sort of homes they're going to have, what sort of lives they're going to live."

The theme of the West and the Democratic future funs through many conversations these days. Says Harry McPherson, a Washington lawyer and once an aide to President Johnson:

"My guess is that the shape of the party, like a shilhouette painting, will be defined by what surrounds it, namely the Republican Party and the Republican government. What will really fire people up and make them Democrats again is Mr. [James G.] Watt," Reagan's interior secretary.

Notes Charles T. Manatt, of California, the new Democratic Party chairman:

"With the exception of Jean Westwood for six months, I'm the first chairman from the West the Democratic Party has ever had. My understanding is we are having our Democratic National Committee meeting in Denver in June, which will be the first meeting in the West in 24 years.

"Balancing the focus on the South, Southwest, and West is something the national Democratic Party very much must do, should do, and under my chairmanship, at least, will do. Not at the exlusion of the East and Midwest, of course, but the focus, the emphasis, the understanding of the West and the Southwest as far as water policy and open spaces and other issues is terribly important to our national party leadership, both in a legislative sense and from the standpoint of future party nominees."

McPherson struck another common note in speaking of the West. "My biggest fear is that the Democratic Party would become exclusively the party representing the decaying, needy cities, mostly of the Northeast, and that the Republican Party will represent the booming, growing parts of the country.

"The West and the South are the parts of the country today where 'yes' is the answer. You know, let's try that. The 'no' comes with time and decay and crime and the subway system failing and the tax burden too great. To think of us ending up by holding on to a few solid old-time districts that have become accustomed to a lot of federal subsidies while the Republicans have that part of the country, moving forward -- that's a bad scene for us, particularly as the demographics have the people moving that way."

Someone like Sen. Edward M. Kennedy (D-Mass.) would not disagree.

But Kennedy, among many others, stresses the need for the Democrats to build a national party and not fall into destructive sectional strife.

"We have seen in the past Congress," he says, "some of the examples of sectionalism such as the producer-consumer issue on energy. We'll face that over a period of time -- about tax rebates in Alaska and about who lives in some of the older cities and states that can't afford heating their homes to a healthy level. That is important not just in narrow partisan political terms, but as to the type of country we're going to be.

"That may very well be as powerful a factor and force almost as the blight of slavery was in this country."

Division is something the Democrats know much about. But for all their present difficulties -- the handwringing, the anguish, the namecalling, the desperate search for unifying issues -- and for all the uncertain nature of their future, the Democrats are in better condition than reported.

From virtually every conversation recorded for these articles, no matter what region the speaker was from or in what political category you placed him, a common theme emerged. Philosophically and politically, it sharply distinguished the Democrats from the Republicans. The issue, paradoxically, was one the Republicans have ridden to national power recently: government.

As Party Chairman Manatt put it:

"The fundamental difference between the two parties quickly reasserts itself, and classically so, in a Republican Reagan era. Republicans believe the government that governs least governs best. You can see that in their approach to the 'safety net' that he talks about and then violates with his proposed changes in Social Security. The Democratic vision is that government is a concept of cooperation whereby people collectively can achieve more of the greater good acting together than they can as individuals."

The old concept still retains power, as political Washington saw recently.

At the Gridiron Club's annual formal off-the-record dinner attended by the president, leaders of both parties, and the press, it was a smashing Republican evening. Reagan and his political success dominated the scene. It fell to Sen. Daniel Patrick Moynihan of New York to deliver the Democrats' traditional response -- and, in this year, defense. After the usual gags, barbs and deprecating humor, he turned deadly serious.

"There are some people in this town," he began, as silence settled over the room, "who remind me of that character in one of Disraeli's novels who is described as a man 'distinguished for ignorance, as he had but one idea and that was wrong.' Such are those who think they've seen the beginning of the end of the Democatic Party."

Total stillness, now, and a clear sense of tension, swept the room. Nothing but intense listeners, now.

"Democrats lost an election last year but we did not lose a tradition. For ours is the oldest political party on earth. We have known good times and bad. Sometimes we have merely endured. But more often than not we have prevailed because at heart we have embodied a great idea, which is that an elected government can be the instrument of the common purpose of a free people; that government can embrace great causes; and do great things."

He ended:

"We believe in American government and we fully expect that those who now denigrate it, and even despise it, will soon or late find themselves turning to it in necessity, even desperation. When they do, they will find the Democratic Party on hand to help. And when at length they learn how much is demanded of those would govern -- we will be back."

It was a great speech, but great rhetoric does not in itself fashion a new political force.

A better definition of the Democrats' present dilemma was given by Peter D. Hart, the Democratic pollster. Rebuilding the party involves two elements, he says -- the mechanics of politics and the party's message. "In 1980, the Democrats were hopelessly deficient in both areas. The party had neither a great jockey nor a great horse; to win, the Democrats need both."

To Hart, as to others, questions about the Democrats' survival come down to a riddle.

"The 1980 election marks the end of a transitional period in American politics," he says. "The question facing the Democrats is whether this is the beginning of the end or the end of the beginning." SEN. EDWARD M. KENNEDY

My continuing star to be guided by is the fact that the Democratic Party has meant open opportunity, the Democratic Party has been a party of decency and compassion and fairness and equity. I think it has had a strong record in the elimination of discrimination and prejudice. We have to continue to apply those values to the problems we face in the future.

I think the president deserves credit for focusing the attention of the nation on the economic issues. . . .The administration has been extremely effective in defining the problem. As Churchill said, those that define the problem win the argument. And they have defined the problem in a way that suits their interests. . . . My concern is that the administration is trying in 10 weeks of proposals to effectively emasculate 10 years of bipartisan progress in a number of different areas. We're challenged now to raise those issues, debate them, offer alternatives, and do it in a constructive, positive way.

Having said all that, everyone has to understand that the Democratic Party is a diverse party of many different interests, and has to understand that the one issue that always has been unifying for the Democrats is the economic issue. Now the idea that Democrats are going to find a silver bullet in terms of domestic policy or foreign policy is something we have to escape from. The Republicans found one during the course of the campaign. What's the problem in the country? Government spending. What's the answer? Supply-side economics. And as H. L. Mencken said, "For every difficult problem there's a simple, easy answer -- and it's wrong."

. . . Whether we like it or not, where the Republicans have been successful is developing slogans consistent with their objectives in government. Democrats understand that these problems are complicated and difficult and don't lend themselves to just slogans and jingles. But I suppose what we have to be able to do is try and communicate in a more effective and thoughtful way that we have both the capacity for effective leadership and administration. And that we're prepared to address the complicated issues of our time in a serious and responsible way. Now how you get that across in a way that catches the imagination and catches the thought process of the American people is yet to be determined.

One thing that concerns me about the Democratic Party: is the Democratic Party trying to be just another Republican Party? This nation doesn't need two Republican parties. Any time the Democrats have tried to be like the Republicans and have gone before the American people, the American people have selected the real thing. That's going to happen in the future. And that's why I think it's so important that Democrats stand for their constituencies now, because their constituencies are being threatened. It's going to be imperative in the rebuilding process that those groups understand who is speaking for them. SEN. JOHN GLENN

The conventional wisdom these days is that we have to out-fund, out-organize, out-computerize the Republicans. That's what everybody talks about. And I agree that we have to do those things, but I would add a big caveat that is of equal or even greater importance.

Any party that will, or even should, long endure is going to do so not just by those mechanics that are necessary but because there was something they stood for. There was some purpose.

We've always been a party that's been concerned about the greatest concerns of the greatest number of people. All at once, in a fairly short time frame, these concerns of the greatest number of people switched. They got the devil scared out of them about where this country was going and about whether our money was going to be worth anything or not. They voted those fears last fall. . . .

We, the Democratic Party, moved many tens of millions of people from this lower status up into pretty good living -- a camper, little white house in the suburbs, the kids in a pretty good school. Not too shabby. Pretty good. And all at once those folks are very much concerned about what their money's going to be worth and where their jobs are going to come from because they've seen several hundred thousand jobs in this country go to Japan, Germany.

We're now being out-competed in some fields and that's a new experience for Americans -- that we're not the innovators. We're not leading in research and we're not coming up with the new ideas that, in a capitalist system, provide all these jobs. So where are they going to come from? Well, they're not going to come because we're starting new WPA programs at this stage and still have the economy that we've known in the past.

If, in our period of time, we have to shift directions to address what are now the greatest needs of the greatest number of people, well, so be it. We have to shift gears and get on with it. SEN. ERNEST F. HOLLINGS

The fact of the matter is that the defeat of the Democrats last fall started about 10 years ago and has been working constantly since that time. Because constantly since that time we have been alienating our constituencies.

Take defense. Oh, we were talking about the heritage of Roosevelt and Truman and John F. Kennedy. With the fallout from the war in Vietnam, the Democrats who recommended anything by way of defense were kooks. . . . Democrats the last 10 years, rather than doing anything, have taken the posture of doing nothing and turned off defense as an issue and turned off everybody interested and worried.

So we turned off the patriotism vote. We alienated the Catholic vote on abortion. We alienated the Jewish vote with our vote in the United Nations. We alienated the young vote; they couldn't see with inflation the chance of owning a home ever. And the blue-collar vote. While we were talking about balancing budgets and paying the bills and cutting down on regulations, we were getting more regulations and bigger deficits and the solid blue-collar worker was going, in large measure, for Ronald Reagan and the Republican Party.

Rather than new ideas, in my opinion, what we really need to do is go back to the old principles, the old basics, that we've had. Someone said that with the alienation of all the groups the Democratic Party ended up with blacks, the ERA, and the gay rights -- and I don't say that derisively. Blacks have elected me for the last several years. They kept the faith, although they had little to keep faith on.

I'd call the administration's hand. I wouldn't have an individual income tax cut. Look, I know how to cut taxes. Every politician wants to cut taxes. But we've got to prove that we are the party of fiscal responsibility. . . .

After all, it was government that really instituted the land policy that opened up the frontier and gave homesteads to millions of Americans. And when it became difficult to travel, it was the government that instituted the land grants that brought the railroads to the West. And it was government, when it became difficult to bring products to market, that developed the waterways and the ports. When we had the industrial revolution, it was the government that put the legal underpinnings to corporate America so they could compete. And at the time of the Depression, when the only question was the economic survival of this country, it was government programs that saved this nation and rebuilt the Democratic Party. And those are our programs and we should be proud of government and quit scaring the American people with all this tommyrot about deregulation, decontrol and get rid of government. That is the Republican cry. The Republicans have never believed in government. They're fearful of it.