Delores Press, Chairman of The Santa Monica, Calif., rent control board and an official of the retail clerks union, came to the Democratic National Convention here as a Kennedy delegate but she is going home determined to work for the Citizens Party Ticket of Barry Commoner and LaDonna Harris.

"I absolutely cannot support Carter," Press declared, ticking off a long list of reasons, from feminist to economic, why the president has lost political favor in her eyes. "Philosophically and politically, I'm with Commoner," she said.

Press is one of a smattering of delegates who came to the Democratic convention to support Sen. Edward Kennedy, were disappointed with his defeat, unmollified by the outcome of the platform battles, and are now looking to a third party for another candidate.

The infant Citizens Party, now seeking to get on the ballot in some 35 states, will draw her support. A tour of the convention floor today turned up other Kennedy delegates, mostly strong union people, who will back the Commoner-Harris ticket.

Commoner, said Mindy Leek, an airline ticket agent from Portland, "is the only option open to me. I've thought about it for the last two months . . . I've been disenfranchised by Jimmy Carter. The Democratic Party is moving closer and closer to the Republican Party."

The only discernible difference in the views of the two women is each's attitude toward the walkout that some union labor delegates plan prior to President Carter's acceptance speech Thursday night. Press will walk. Leek will not. But Leek will be absent from the hall.

The walkout will be led by William W. Winpisinger, a delegate from Maryland and president of the International Association of Machinists and Areospace Workers. The IAM has 91 members among the various delegations and most are expected to join the walkout, as are other union delegates.

Late yesterday, large yellow buttons reading, "I'm walking with Wimpy," blossomed on the shirts, jackets and blouses of delegates from several states. One of the pins was prominently displayed by Jerry Oliviera, an alternate delegate from Annandale, Va. "Barry Commoner is the only Democrat running on the Democratic platform," he said. "Carter is a Republican on a Republican platform under a Democratic title." Oliviera, an airline mechanic, said he will join the walkout.

The link between the IAM and the Citizens Party is somewhat tenuous, according to Bill Zimmerman, Commoner's campaign manager. He said Winpisinger had personally indicated his support for the Citizens Party ticket but the IAM would not make an endorsement until it holds its convention in Cincinnati later this month. Zimmerman said an estimated 100 of the Democratic delegates would support Commoner.

The goal of the Citizens Pary, Zimmerman said, is to get 5 percent of the total popular vote, about 4 million votes, so that his party can qualify for an estimated $10 million in federal campaign funds, for both 1980 on a retroactive basis and for the 1984 campaign.