Like typical blind dates, black and Hispanic voters are always matched up as a winning political pair, but have never hit it off in a big way. Both groups feel a bit like wallflowers in the Democratic Party. Both face high unemployment, housing problems, and some ethnic discrimination. Both count heavily on public education to improve the lives of their children.
But most political alliances between blacks and the burgeoning Hispanic population have been short-lived.
There are some signs lately, however, of a greater willingness between the black and Hispanic communities to throw their political fortunes together.
Mario Obledo - a former official in Gov. Edmund G. Brown's administration and president of the nation's largest Hispanic organization, the 109,000-member League of United Latin-American Citizens (LULAC) - has been making broad agreements with major black groups in quick succession.
Mr. Obledo signed a formal agreement with Jesse Jackson's Operation PUSH (People United to Serve Humanity) in July for cooperation on voter registration drives and economic issues. In August, he signed an accord with the Urban League and now is talking to Benjamin L. Hooks of the National Association for the Advancement of Colored People.
Making local chapters mesh their efforts will not be as easy as signing formal agreements, Obledo concedes, but he calls the prospects promising. ''We've just been born, so to speak,'' he says of the alliances, ''and it's a long-term process.''
It was Harold Washington of Chicago that brought the ''rainbow coalition'' strategy into the national news by winning the mayor's seat with his power base in an alliance of ethnic minorities. LULAC was active in his campaign.
Even more recently, Melvin H. King of Boston, a black and former state legislator, was one of two finalists in that city's race for mayor. He earned a spot on the Nov. 15 ballot by putting together a rainbow coalition of his own.
Now Jesse Jackson is carrying the concept further in his bid for the Democratic presidential nomination.
What is needed to build a political base on such an alliance, politicians and strategists agree, is a charismatic candidate who can draw people who don't usually vote to the polls.
The candidate who has done this better than anyone before or since, agree black and Hispanic politicians, was Robert F. Kennedy, whose presidential campaign was cut short by an assassin in 1968.
Larry L. Berg, who worked with that Kennedy campaign, found that the alienated or apathetic young people in ethnic minority communities could be stirred up by a charismatic candidate, ''but when RFK was gone, the young voters were gone.''
LULAC is not likely to back Mr. Jackson's candidacy directly. Its voter-registration drives are nonpartisan. But the voters that these drives aim to bring to the polls are the kinds of voters Jackson's campaign is expected to inspire. The goal of the LULAC drive is to register a million Hispanic voters by the 1984 election.
Obledo himself is enthusiastic about Jackson's campaign. ''It means a lot of important issues are going to be discussed.'' The issues important to blacks are the same issues that matter to Hispanics, in Obledo's view, with the exception of bilingual education.
Taken together, Obledo points out, the two ethnic communities represent some 50 million people, so an alliance of interests has great potential.
But Obledo speaks best for people on the liberal side of his community. Hispanics overall are neither as liberal nor as Democratic as blacks. According to the Field Institute, a California polling firm, California's Hispanics fall halfway between whites and blacks in ideology and party ties - blacks being more Democratic and liberal than whites.
Yet political friction between blacks and Hispanics in the past has not been so much a matter of issues and ideology as of competition, the sense that progress for one comes at the expense of the other.
Many black politicians in this state have overcome this tension. Most notably , Tom Bradley won 72 percent of the Hispanic vote in his most recent reelection as Los Angeles mayor.
Yet Mayor Bradley, who has never had a reputation for charisma, wins Hispanic votes without attracting large Hispanic turnouts. Managing editor Mark DiCamillo of the Field Institute's California Poll notes that one reason Bradley was narrowly defeated in his 1982 gubernatorial bid was a lower-than-expected Hispanic turnout at the polls.
It will take someone with strong vision and charisma to overcome narrow loyalties and forge a broad, active base of ethnic minorities, says California assemblyman Richard Alatorre (D) of Los Angeles, who is known for his political street sense.
Jackson is still an unknown factor among Hispanics, Mr. Alatorre says, observing that Jackson has yet to make a strong bid for Hispanic vote. ''Many of us are already committed to other candidates,'' he says.