The unity that the Democrats made such a point of on national television last week is showing some dividends in California this week. Interviews with two California delegates each from the Mondale, Hart, and Jackson camps upon their return home indicate that convention excitement has spilled out among rank-and-file voters. The Democratic delegates say they hope the party can capitalize on California's overall Democratic majority, minorities who are inclined to vote for the party's candidates, the appeal of a female vice-presidential candidate, and the desire to unseat President Reagan.
But in Ronald Reagan's home state, which has the biggest block of electoral votes, 47, Walter Mondale may be facing his toughest battle this fall.
Oscar Thompson, a retired auto worker who now is a bank security guard, spent the spring walking the precincts for the Rev. Jesse Jackson. Since returning home to Carson, Calif., fresh from the Democratic convention, he's been back out on the streets again pushing a new candidate - Mondale.
An elder in the Judson Baptist Church, Mr. Thompson says his largely black congregation this past Sunday ''seemed to be pretty elated about the convention and satisfied with the ticket. ... Even my wife is saying she'll vote for Mondale.''
Neighbors in the blue-collar, racially mixed section of central Long Beach showed up at Shirley Guy's front door upon her return from the Democratic convention wanting to know what they could do to support the Mondale-Ferraro ticket.
''People I don't really know stopped by, and they were really excited about Geraldine Ferraro and the positive atmosphere of the convention,'' says Ms. Guy, a Mondale delegate and executive director of the Teachers Association of Long Beach.
And in the affluent west side of Los Angeles, Estella Epstein, a Hart delegate, gauges that from the excitement of neighbors who stopped by on her return, ''the woman on the ticket is an exciting prospect for a lot of people.''
There won't be much trouble mustering support for Mondale in her heavily Democratic district this election season, says Ms. Epstein. Indeed, she notes, the wealthy west side will undoubtedly be successfully tapped by Mondale fund-raisers even though it was Hart territory.
But returning delegates also balance allegiance to Mondale with the assessment that it will be an uphill battle against Californian Ronald Reagan.
''Hispanics alone could win the vote in California'' if that minority vote is tapped in the campaign, speculates Mondale delegate Bob Morales. But in his Montebello community east of Los Angeles, says the young aide to state Sen. Art Torres, the Hispanic and Asian residents ''felt neglected during the primaries because no major events [with the candidates] were scheduled in that district.''
He says his Hispanic community is ripe for any Democratic presidential candidate because of disaffection with the Reagan administration and because ''they view Mondale as making a bold move in selecting a woman as a vice-presidential running mate.''
Paid this spring to help run the Mondale primary campaign in California while on leave from his job, Mr. Morales says his efforts for the Democratic ticket will be keyed directly to the amount of money the campaign plows into California - that he can't afford to do the full-time work of registering new voters, walking precincts, and organizing the local campaign if he's unpaid.
Morales and some other California Democrats speculate that Mondale might want to concede the state to Reagan rather than spend enormous amounts of money here. But Mondale campaign officials claim that was a rumor fueled solely by comments from Willie Brown, the powerful speaker of the California Assembly, despite the fact that campaign plans have not been finalized.
''The black vote is the most consistent Democratic vote; it never goes anywhere else. It's the independent, yuppie vote that needs an organized effort to keep them with us,'' says Inola Henry, a Hart delegate from the largely black 28th Congressional District that was nearly unanimously in favor of Jesse Jackson.
''The reaction here seems to be very much unified. I guess unity isn't rhetoric after all. I fervently support Mondale, and that's not out of cynicism'' that there's no one else for Democrats to vote for, says Ms. Henry, a black elementary schoolteacher and vice-chair of the Los Angeles County Democratic Central Committee.
''On principle, on a gut level, I agree with Hart's philosophy, but pragmatically I'm able to understand that most Americans don't agree with me,'' she says, explaining how she now can support Mondale.
Her campaign mission this fall, says Ms. Henry, is to make speeches and to walk precincts trying to keep Hart delegates from slipping out of the Democratic camp.
For Barbara Lubin, a Jackson delegate from Berkeley, the fog of disappointment hasn't cleared yet. The Jewish political activist, mother of a disabled youngster, Berkeley school board member, and part-time soda fountain worker, says she became a Democrat just to be a Jackson delegate.
''I walked the streets for Jesse; I'm not going to do it now. I'm tired of voting for the least-awful person. . . . I would have a difficult time supporting a president who doesn't support cutting military spending and no first use (of nuclear weapons),'' she says of Mondale, who did not support the two Jackson platform planks on those two issues.
But Ms. Lubin admits that her diverse but basically liberal district is likely to support the Democratic ticket because of Ferraro and because the only other choices are not to vote or to vote for Reagan.