Unless the Democratic Party wants to surrender control of its presidential nomination to the news media, it must find a way to keep states from bunching primaries at the beginning of the process, pollster and strategist Patrick Caddell told the party's rules-writing body yesterday.

Caddell said the "front-loading" of primaries and caucuses in recent elections has created a "de facto national primary" that neither gives voters enough time to scrutinize outsiders who suddenly break out from the pack, nor gives long-shot candidates enough time, once they emerge, to build coalitions necessary to win and govern.

In 1984, 40 percent of the party's convention delegates were selected by the third Tuesday in March -- just two weeks after the opening of the party's 13-week delegate selection "window." In 1972, 13 percent were selected by that date.

That compression of events, Caddell said, enabled Sen. Gary Hart (D-Colo.) to leap from being "a total unknown to coming within a hair" of eliminating former vice president Walter F. Mondale in the span of two weeks last year.

During that time, Caddell said, Hart was going from "airport to airport, holding press conferences," with no time to build a national organization or create a coherent strategy. It was eventually his undoing.

To reverse that trend, Caddell proposed that the party offer incentives to states that wait until the middle or end of the process. One such incentive could be the opportunity to hold primaries in which the winner gets all the delegates or the winner gets more delegates, increasing the importance of the later contests.

Caddell's prescription got an interested hearing from the 51-member Fairness Commission, which is to propose rule changes to the full Democratic National Committee by the end of this year.

But its comprehensiveness appears at odds with two prime objectives set forth by DNC Chairman Paul G. Kirk Jr. and Fairness Commission Chairman Donald Fowler of South Carolina -- to simplify the rules and to avoid any major overhauls.

"It's too Rube Goldbergesque," said Morley Winograd, a commission member and chairman of an earlier rules-writing panel that had proposed -- to no avail -- a similar "sliding threshold" approach in the late 1970s.

In addition to the discussion of timing, the commission yesterday heard presentations on a variety of thorny issues, but it took no votes and indicated few preferences.

When Kirk created the panel, he said he would look with favor on two changes: a lowering of thresholds (the percentage of the total vote that a candidate must get before becoming eligible for any delegates) from 20 percent to perhaps 15 percent to enable long-shot candidates more chance to collect delegates; and a delay in the selection of so-called superdelegates -- the 568 unpledged party leaders and elected officials -- until the end of all primaries.

While there was broad agreement yesterday about the second change, there was a rift over thresholds. Ron Walters, an adviser to the Rev. Jesse L. Jackson's 1984 campaign, said any system that allowed a candidate to win nearly 20 percent of the primary and caucus votes but receive just 11 percent of the delegates -- as Jackson did last year -- created a "perception" of unfairness that would turn potential voters away from the party.

Rep. Robert G. Torricelli (D-N.J.) countered that any lowering of thresholds would hold back the necessary "winnowing" of the field.