While tearful supporters of Sen. Joseph Biden from Iowa to New Hampshire cursed real and imagined architects of his fall, political lieutenants close to him were thankful for the early end of a presidential candidacy they now feel never should have been.

In private, these aides blame neither rival presidential campaign operatives nor sensation-seeking reporters. They blame their own candidate, because of his managerial deficiencies and, more important, because they began to believe that he was at heart a synthetic candidate with nothing to say.

Biden's early fall, before his improving Iowa organization could propel him toward the nomination, may thus be considered evidence that the system works.

But the short, unhappy presidential candidacy of Joe Biden also exposes the systemic problems that bedevil the Democratic Party. His fate was sealed by an inability to reconcile demands of liberal special-interest groups with the necessity of appealing to a broader base.

The perception of just such a Biden appeal explains why a 45-year-old senator from a small state with no record of leadership in the Senate not long ago seemed to many Democratic insiders their most viable presidential candidate. His oratorical technique, television appeal and charismatic personality had targeted him for the past decade as the candidate of the future.

After the party's 1984 debacle, he was viewed by Walter Mondale's backers as a Democrat with appeal for mid-America. John Reilly, Mondale's law partner and senior political adviser, signed on with Biden. Chicago Democratic insider Bill Daley, who had travelled with Mondale in 1984, commuted to Washington to serve as Biden's political director. Chicago businessman and political fund-raiser Tom Rosenberg, viewing Biden as a candidate who could broaden the party's appeal, raised money for him.

From the start, the campaign degenerated. Tim Ridley, a bright young pro, never was able to get control of it. The campaign ignored old pro Reilly, who in turn ignored the campaign. Political consultants Bob Shrum and Dave Doak, key Biden adviser Patrick Caddell's former partners and current enemies, jumped to Rep. Richard Gephardt.

This chaos might have been overcome if the candidate had had something to say. But he never resolved his inclinations as a middle-class urban Catholic with his willingness to placate special interests. He praised the contras in the Senate, then voted against them. He planned to confront Jesse Jackson, then softened his criticism. Biden's style was dynamic, but his message was diffuse.

The early solution was posed by Caddell's "new generation" speech, which conveyed hope and inspiration without taking policy stands. Although the speech has become a butt of ridicule in Democratic circles, from 1984 through 1986 it excited tremendous enthusiasm whenever and wherever given. Biden's 1985 Des Moines rendition made him Iowa's winter book upset favorite.

But during 15 years in highest-level Democratic politics, Caddell has become a contentious figure, and his mere presence served to rip apart an already fragmented campaign. Biden staffers were delighted this year to see him temporarily in California as a visiting professor. If Biden found it difficult to live with Caddell, he found it even more difficult without him. "Without Pat around," an insider told us, "Joe didn't really have anything to say." This is cited as an explanation for the Neil Kinnock imitation.

At this critical stage, the Bork confirmation hearing approached. Again, Biden's instincts clashed with Democratic realpolitik. Prior to the nomination, he had publicly promised that as Judiciary Committee chairman he would defy special interests and vote to confirm Judge Robert Bork for the Supreme Court. Yet, aides tell us, the reason he announced his opposition before the hearings was his inability to face pounding from Bork-hating pressure groups.

The anxiety induced in Biden by these hearings is pictured by intimates as overwhelming. For weeks before the avalanche of exposes hit, the senator was described by an aide as having been in a "funk" over the hearings.

The consensus last week to end the campaign was clear. Actually, he announced for president June 8 only after internal debate and a split decision. When the senator's managers learned last week that back in June he had sent for his Syracuse law school records, but told no one, doubts were confirmed that this was not the man to be or run for president.

What remains to be seen is whether internal Democratic contradictions that reduced Biden to gimmickry might yet plague one or more of his surviving opponents.