LOS ANGELES–After dinner with Al and Tipper Gore in St. Louis Monday, and a late-night flight that got him here just after 1:30 a.m., Joe Lieberman got up early Tuesday to sing “Happy Birthday” to Maxine Waters. She is the vocal California congresswoman whose voice rises out of the most liberal corners of the Democratic Party.

The overture to Waters was part of a larger one to the Congressional Black Caucus and in some ways mirrors the work that Al Gore may be called upon to undertake to bring the moderate and liberal wings of his party together. For Lieberman the move seemed to bear immediate political fruit.

In recent days, Waters had expressed some dismay at Gore’s choice of Lieberman to be his running mate. She said she was uncertain about Lieberman’s past and current positions on affirmative action and on the use of school vouchers, issues critical to her constituents and to many African-American voters. As a result, she said, she was unable to embrace the ticket. The public stiff-arm by so prominent a member of the black political class worried Democratic officials for more than one reason. First, it raised the touchy issue of how black voters would respond to a Jew on the ticket. There is continuing political unease between Jews and blacks on some issues, and how black voters would react to Gore’s choice of Lieberman remains one of the unanswered questions of the campaign.

Warmly embraced by much of the African-American political leadership, there was an unstated understanding that Lieberman would have to be sold, and vigorously so, in some parts of the black community.

When the head of the Dallas chapter of the NAACP made what were clearly antisemitic remarks, the immediate repudiation of him by other black leaders heartened those Democrats who understand how crucial enthusiastic black support would be for the Gore-Lieberman ticket. Twenty percent of all the delegates here are black.

With Waters’s questions, there was a quiet worry that legitimate political disagreement could play into some undissolved, if unstated, antisemitism.

Waters was clear that all she wanted was answers to the question of where Lieberman was on a few issues. With the right answers, she said, she would happily campaign with and for Lieberman and Gore.

By Tuesday, the Lieberman–African-American issue had taken on a life of its own. Harvard professor Cornel West declared Gore’s selection of Lieberman “a slap in the face” to African-Americans because of his position on affirmative action. Lieberman said that West is simply wrong about his position.

When the newly minted vice presidential candidate took to the stage at the Bonaventure Hotel to chants of, “We want Joe. We want Joe,” the welcome seemed genuinely warm, and Lieberman thanked a lot of people on the stage with him. Then he said: “I don’t know if I’m telling a secret here, but do you know that today is Maxine Waters’s birthday?” Waters, notably, was not on the stage. But in the applause that followed, she rose to accept the birthday greetings and to acknowledge a fairly uneven rendition of “Happy Birthday.”

Lieberman had come to explain, and he did. He has always favored affirmative action, he does now, and always will, he proclaimed. His concern was about some affirmative action programs that were in danger of becoming “quota” programs, and he quickly signed on to President Clinton’s “mend it–don’t end it” approach to the problem. That seemed to satisfy the crowd. He said he supported the experimental use of vouchers but that his focus would be on improving public education.

When he left it was to applause, and some of that may have been secured before he had said a word.

Lieberman was introduced by Del. Eleanor Holmes Norton of the District of Columbia, who, like Lieberman, attended Yale Law School. She praised him for his “perfect voting record on affirmative action” and issued a reminder that trying to manage political tension is nothing new for Democrats.

“You know who taught me how to live with differences within the Democratic Party?” she asked. “Bill Clinton, Bill Clinton and Al Gore.”