Stuart E. Eizenstat, President Carter's chief domestic affairs adviser, called a news conference at Carter campaign headquarters yesterday to praise the newly drafted Democratic Party platform as a reflection of the best Democratic traditions and a document that can unify the party.

But also yesterday, Sen. Edward M. Kennedy (D-Mass.) told reporters that the platform draft indicated the party was preparing to "turn its back on the millions of Americans who are unemployed or . . . who are being victimized by high interest rates or high rates of inflation."

Both statements were symbolic of the current strains in the party as the full Democratic platform committee assembles in Washington today to deliberate on the draft completed by a 15-member subcommittee this week.

Eizenstat met with reporters in part to counter news reports and charges from the Kennedy camp that the subcommittee had largely ignored Kennedy proposals in its draft platform, which itself contradicted past party positions on some issues.

Eizenstat denied both interpretations, insisting that Kennedy's delegates made a substantial contribution to the draft, and also insisting that the document was "consistent with the thrust and direction of previous Democratic platforms."

Eizenstat's public appearance was symbolically significant because of who he is. Although he has no formal position on the platform committee or drafting subcommittee, delegates in both camps agreed he dominated the drafting procedure as the president's man on the spot.

Kennedy's demurral from rosy adminstration assessments of the draft platform symbolized his persistence as a challenger to Carter even after the primaries and caucuses have put him behind the president by nearly 2 to 1 in all delegate headcounts. The Carter camp thinks Kennedy should drop out of a hopeless race and help unify the party, but Carter and his aides decline to say this openly.

Instead, the Carter campaign has decided to look for gestures to demonstrate a sympathetic attitude toward the challenger, but also insisting on its position in all direct disputes on major issues.

Thus the Carter camp offered five of the 15 seats on the platform drafting subcommittee to Kennedy supporters, retaining nine for itself and one for an "independent," Sen. Daniel Patrick Moynihan (D-N.Y.).

The result was to perpetuate the status of the Kennedy camp as the only recognized "opposition" to the Carter administration within the party. In practice, all serious challenges to Carter administration policies in the drafting subcommittee came as proposed Kennedy planks to replace Carter planks.

This effectively excluded other liberal elements in the party that would like to push the administration further to the left before the fall campaign, but who are not irrevocably tied to Kennedy's fate.

Some Democrats believe it is those elements that will be crucial to Carter's reelection chances, and some of them expressed strong displeasure with the outcome of the platform drafting procedure.

"This thing is a scandal," one union leader said yesterday. He went on to describe the organizers of the procedure as "dumb bastards." A liberal Democrat who holds an appointed office in the administration expressed dismay at the polarization that the platform drafting apparently has accentuated.

The Kennedy campaign will reoffer many of its proposed planks when the full platform committee meets this weekend.

Peter Edelman, Kennedy's chief issues adviser, said yesterday that the Kennedy proposals would be boiled down into "a manageable number" to be offered as amendments to the draft.

Though Eizenstat insisted that the draft platform included many Kennedy proposals and reflected some concessions by the Carter camp, Edelman disagreed.

"They didn't make any major concessions," he said. The Kennedy language that was adopted, he added, consisted largely or proposed planks on subjects like consumer protection, antitrust policy and the Occupational Safety and Health Administration, about which the Carter staff's original draft had virtually nothing to say.

"We greatly appreciate the constructive and cooperative efforts" of Kennedy supporters on the drafting subcommittee, Eizenstat told reporters. "We left [the drafting procedure] feeling better about each other than might have been the case going in."

Eizenstat praised the draft as a platform on which all Democrats could run and win in November. He said it contained "a program based on realistic solutions, and not simplistic solutions or rhetoric."

He agreed that there had been no compromise with the Kennedy faction on basic economic issues that have been at the heart of Kennedy's campaign -- immediate wage and price controls, recontrol of oil prices and an immediate $12 billion antirecession program, for example.

Eizenstat said these were positions Kennedy was insisting on as part of his continuing candidacy, and agreed that the Kennedy camp had no interest in compromising on any of them.

The Washington Post reported incorrectly yesterday that the new draft platform (the text of which will not be released until this morning) substantially weakened the party's support for causes backed by organized labor. Eizenstat listed numerous planks in the draft supporting labor's positions.