Well before Ronald Reagan defeated Walter Mondale last fall, it was apparent that the Republican Party had all but conceded the black vote to the Democrats. It was also apparent that, despite any disappointment blacks may have harbored over the treatment of the Rev. Jesse Jackson and a lack of influence over the party's platform, they would again vote almost exclusively for the Democratic ticket.

The landslide victory for Reagan, despite a monolithic black vote for Mondale, has raised some serious concerns. It has prompted new tactics by the Republicans to win the support of successful middle-class blacks. And as Republicans and conservative blacks accuse the Democratic Party of taking black voters for granted, the post-election soul searching by the Democratic Party has disturbed some black Democrats. They fear that the party may place too much emphasis on winning back the more conservative Democratic voters who preferred Reagan. The Reagan reelection was also a serious blow to the affirmative action programs that were designed to redress past discrimination.

The moment has come for the nation's black leadership, and those blacks who would compete for leadership status, to redefine the needs of black Americans and decide who or what should address those needs. The central question is whether we blacks must assume responsibility for addressing black needs or whether the responsibility for change should fall at the collective feet of society, the federal government and the court system. Another question concerns blacks' loyalty to the Democratic Party and its ability to serve black interests. Finally, are the nation's traditional black leaders and institutions capable of setting and meeting those needs, and will it be possible to count on unified action from blacks if the gap between successful blacks and the "underclass" continues to widen?

Here are some of the thoughts of some well- known black leaders.

To Eleanor Holmes Norton, former director of the Equal Employment Opportunity Commission, the 1980s agenda is far more complicated than that of the '60s.

It consists of a)developing a stable entrepreneurial class of blacks, b)reversing the growth of a large "underclass" of poor blacks, c)stabilizing the black family at a time when more than half the black families below the poverty level are headed by single women, d)stemming the growth of black male and teen-age unemployment, and e)closing the achievement gap between black and white students.

"We are faced with issues in which the solutions and remedies are very unclear," Norton says. "There is no set of clearly defined goals as magnetic as the overthrow of segregation. The agenda is more complex and subtle now."

The question of black leadership and unity is also more complex. When the civil rights movement began, the number of significant black leaders was smaller. They were more readily recognized -- the Rev. Martin Luther King Jr. and A. Philip Randolph. Black unity was relatively simple to achieve because we were all "have-nots" then. But the gains of the civil rights struggle have resulted in potential black leaders' springing up in local and state politics, in private industry and other areas. In that lies a potential schism between success for some blacks while others are as poor as before.

"We are not as together as we used to be," says Vernon Jordan, former president of the National Urban League. "That is not inherently damaging, but the problem is how do you make common cause between the (black) 'haves' and 'have-nots'?"

Georgia state senator Julian Bond feels that too many blacks seek a single national leader.

"We fixate back on his (King's) period and say 'Gee, how great we were then.' It hurts us to look only for another King."

Jordan says the "second metamorphosis in black leadership" -- the elected officials, black leaders in public and private institutions, black businesses and entrepreneurs -- should be utilized.

In fact, conservative blacks within the administration who claim there is no real problem of racial discrimination may have substantive common ground with traditional black leaders with whom they have been carrying on a bitter debate. It exists in the realization that the strength of the black community's gains in an economic, political and social sense should be the chief means of addressing some of the most pressing problems blacks now face.

An example of one of those problems and efforts to dealt with it: black teen-age pregnancy and the campaign being waged by blacks in New York City to tell young black men: "Don't make a baby if you can't be a father." Black Enterprise magazine and black professionals from CBS Records were called in. Local black professors were asked to help. The second-largest black advertising company in the country agreed to help. James Ingram was asked to sing the radio spot, and prison inmates raised $2,000 and made posters for the campaign.

"This is an example of the black community mobilizing its resources to do something about a problem," said John Jacobs, head of the National Urban League.

Whether we decide to remain steadfast Democrats or investigate other alternatives, self-help in the form of money, leadership, strategy and skills within the black community must be brought to bear on the problems confronting blacks at a time when there is no reason to believe that others, in goverment and elsewhere, will be willing to do those things for us.

Jacobs said that hunger and unemployment are national problems that require federal intervention, but, he added, "we are willing to carry our load. It is of paramount importance that the black community identify our top priority problems and take them on ourselves."