Washington — A young businessman, using a reporter's shoulder to keep his balance, climbed onto a fence to get a better view of Gary Hart as he addressed an outdoor lunchtime rally recently.
''This is the only Democrat I could vote for,'' the young man confided. ''Walter Mondale? No way! When Mondale was in the White House, he didn't put a chicken in every pot. He didn't even leave the bones. I'd vote for Reagan first.''
As Senator Hart spoke, however, the young man began to have doubts. When Hart vowed to cancel the B-1B bomber and the MX missile, he climbed down off the fence and said: ''Oh, I don't like that. I want a strong military.''
Democrats have been a party much like that young man this spring - a party whose faithful have wavered from candidate to candidate, a party without a burning issue like Vietnam or Watergate to pull it together.
Many Democrats, like the young man, grumble that if the eventual nominee is Mondale or Hart or the Rev. Jesse Jackson or Candidate X, they will desert the party and vote for President Reagan.
Political pollsters, who have been trying for months to figure out what the public wants in this election year, say all of this indicates the Democrats are in deep trouble.
It's not just that Mr. Reagan looks great in the polls. He does. He's defied the usual trends and climbed handsomely in the ratings since early 1983. It's worse than that. Even though Democratic pollsters have uncovered what they consider serious Reagan weaknesses, no Democratic candidate has been able to dent Reagan's shiny armor.
Why? Democrats don't like talking about it. But when you look at the Democratic field, neither Mondale, Hart, nor Jackson seems in a position to exploit Reagan's flaws.
First, however, let's look at Reagan's current strength, and how significant it may be.
If one looks back at all the modern presidents beginning with Harry S. Truman , one finds that Reagan is doing something that virtually no one else has achieved. Just about every president during his third year in office has seen himself grow less popular. But not Reagan.
Truman's public approval rating, for example, fell a stunning 21 points during his third year. Lyndon B. Johnson skidded 14 points. John F. Kennedy was dropping fast prior to his assassination. Richard M. Nixon fell seven points. Jimmy Carter was on a downward slide, although the Iranian hostage crisis sent his ratings briefly upward.
Reagan, however, has defied tradition. During his third year, the polls rose 19 points. And they have stayed up. Only Dwight D. Eisenhower (up 7 percent his third year) had a similar performance.
Reagan has been flexing his political muscles in other polls as well. A Gallup poll in April found that for the first time since 1981, Americans say the Republicans, rather than the Democrats, are better able to keep the country prosperous.
In California, a poll by Mervin D. Field found that a record number of people there now describe themselves as better off financially. Some 55 percent of all Californians say they are better off today than a year ago - the largest one-year increase on record. And a majority (51 percent) say they expect to be better off a year from now, another record high, and more good news for the man in the White House.
Democratic candidates have been saying that despite this rosy picture, it can't last. Reagan has to start falling, they argue. After all, what about the $ 200 billion federal deficit? But pollsters don't see much hope for the Democrats in that issue either. The Garth Analysis, a political research report out of New York City, probed the deficit question and quickly waved a warning flag at Democrats. Said David Garth: ''Democrats will only hurt themselves by trying to pin the blame for the deficits on Reagan.''
His findings: By a margin of 44 to 30, registered voters say they think the Republicans, not the Democrats, are better able to handle the deficit. Further, only 12 percent of US voters blame Reagan for the deficits. Nineteen percent blame the Congress, 21 percent blame previous presidents, and 23 percent put the onus on general economic conditions.
Harrison Hickman, who was a strategist for John Glenn's now-defunct presidential campaign, says that despite all this upbeat news for Reagan, the President has important vulnerabilities this year. These weaknesses have been known to all the major Democratic campaigners, Mr. Hickman notes, but so far no one has been successful at taking advantage of them.
The pivotal phrase this year - the theme that could put a Democrat back in the White House, Hickman says - is ''leadership for the future.'' Hickman, who is vice-president with Hamilton & Staff, political consultants in Washington, says those words summarize what the voter is looking for. ''The American people think we had a series of presidents, beginning with Lyndon Johnson, who let us go too far,'' he explains.
This series of presidents let the people become irresponsible and weak, Hickman notes. They encouraged people to demand too much of government.
''Jimmy Carter came along and attempted to tell the American people that,'' he says. ''But he eventually became a personification of weakness. ''So people turned to Reagan for strength. And they have remained with him, even though the people don't see Reagan as a person really attuned to the future.''
The President, Hickman says, gets high marks from the public for two reasons. They give him credit for cleaning up the ''mess'' left by Mr. Carter. And Reagan also benefits when he is compared with those men who want to replace him.
Donald Ferree, an official with the Roper Organization, adds that while Reagan may not be seen as a man of the future, he gets political credit for making changes that the public likes: the military buildup, and a better economy.
Admittedly, says Mr. Ferree, there is some discomfort among voters on both these areas. In the military area, people argue about whether the Pentagon is wasting money. They debate specifics, such as whether the United States really needs 15 aircraft-carrier task groups. And they fret about nuclear weapons. In the economic area, voters wonder whether the recovery will last. And they ponder the meaning of the deficit (though the average voter, Ferree says, worries a lot less about the deficit than economists do.)
But such specifics get brushed aside when people are picking the national leader. In the end, any presidential election, including 1984, comes down to two questions, says Ferree: Has the man in office done well enough to be reelected? Is the challenger a better person?
''Ronald Reagan's standing on the first question is a lot better now than Jimmy Carter's was in 1980, when the public had answered, 'No,' '' Ferree observes. This will automatically make the Democrats' job much harder this year, he suggests.
Political pollsters, however, say Reagan does have soft spots that give the Democrats a fighting chance.
Americans are very concerned about the future, especially as it relates to jobs. They worry about Japanese competition. They are uncertain about the effect of robots and computers. They worry about energy supplies, the effects of huge corporate mergers, the internationalization of industry, and the ability of Washington to hold down inflation.
Hart's future-oriented campaign shows that there is a longing among voters for someone willing to address these challenges. Democratic planners think they can show that Reagan isn't attuned to such concerns.
Democratic pollsters also say the public wants a president who demonstrates more compassion than Reagan does. The public also doesn't like Reagan's outspoken ideological tone on certain issues, such as relations with the Soviets. The public wants solutions, not confrontation. They want balance, not a rightward tilt, to the government.
At the same time, the public adamantly wants to avoid going back to what is called the ''big spending'' ways of the past. And this causes problems for the Democrats, especially if Mondale is the nominee.
Mondale, some pollsters say, is conceptually further back in time than Reagan , in the view of the public. Mondale was part of the Carter White House, but to the public he goes back even more - to the 1960s and to those same high-spending Democrats ''who got us into all this trouble.'' If Reagan is able to tag Mondale with the label of a '60s Democrat, pollsters say, the President may be able to breeze to victory.
If Mondale is the nominee, pollsters and political strategists say, he will also need to do a better job than he has so far of shaping the issues against Reagan.
''The Democrats have yet to find a great mobilizing issue,'' notes one party strategist.
At present, the main thing the Democrats have working for them is anti-Reaganism among some sectors of the public.
A study of the political outlook in the newest issue (February/March) of Public Opinion magazine observes that 64 percent of those who currently support Mondale explain their choice in ''anti-Reagan terms.'' Mondale's own personal support seems soft and indecisive.
By contrast, 71 percent of those who back Reagan say their decision is firmly rooted in his policies - an excellent sign for the President.
Why is this important? One need only think back for a moment to that young man standing on the fence at the Gary Hart rally.
Just being against Ronald Reagan won't necessarily be enough. Democrats need to unify, and to draw independent voters, if they are to win. ABC News exit polls, taken during this year's Democratic primaries, show how serious Democratic disunity could be in 1984.
Illinois was an example. Gary Hart drew 35 percent of the Democratic primary vote there. ABC polls show that one-third of those Hart voters said they would abandon the party and support Reagan if Mondale were the nominee. Another third of Hart's supporters said they wouldn't vote at all with Mondale heading the ticket. Similar results were found in Massachusetts, Florida, and elsewhere. In fact, in Massachusetts, nearly half of those who voted in the Super Tuesday primary said that if Mondale were the party's choice, they would either back Reagan or stay home.
Many of those who abandon the party with Mondale as its leader are those same Yuppies (young urban professionals) who have been among Hart's strongest supporters this year. While many of them either want Hart, or no one at all, others flip over to the Republican column without Hart on the ticket.
California pollster Field is one of those who sees the Democrats having a tough time getting their act together. Nothing anyone says about Reagan appears to hurt him, Mr. Field observes. Nor have the Democrats come up with a clear policy package that could win over such groups as the Yuppies.