The Rev. Jesse Jackson's "Push for Excellence" benefit concert at the Warner Theater Monday night ended with Jackson at center stage, invoking the dream of Martin Luther King Jr., the Selma-to-Montgomery civil rights march, and proclaiming his pride at having a black mayor in Atlanta, a capital of the Old South.

The chorus line behind him was a typical Jackson coalition: four members of Congress, two university presidents, the head of the National Council of Negro Women, the mayor of the District of Columbia, Jackson's 18-year-old son, comedian Bill Cosby, singer Roberta Flack and a regional executive of the Coca-Cola Co., the target of a Jackson-led boycott two years ago.

Arms crossed, hands joined, their bodies swayed as they sang:

O, Freedom. O, Freedom.

O, Freedom over me.

And before I'd be a slave,

I'd be buried in my grave.

Going home to my Lord to be free.

And Jackson's voice boomed above it all, preaching the politics of a black bid for the presidency.

"We are going to the White House," Jackson said. "We are going to make the journey from the guttermost to the uppermost . . . from the slave ship to the championship. We may not all get there, but our people will make it.

"In a mere 18 years since the Selma march , we've come from the back roads of Alabama to the main street of Atlanta," he said, "still moving north, to 1600 Pennsylvania Avenue."

In many respects, Jackson's brand of political activism represents the best and the worst of the embryonic effort by several civil rights leaders and disgruntled black Democrats to determine if a black presidential candidate is an idea whose time has come.

While two dozen members of a self-ordained ad hoc group are studying the matter and drafting a possible platform, Jackson is giving the notion visibility and forcing the issue.

"If you just wrote up the theoretical position that blacks should run as a moral or academic position it would create no political interest," Jackson said. "But the fact that someone may carry the banner is what makes it an issue of great interest."

Jackson, 41, president of Operation PUSH (People United to Save Humanity), a Chicago-based civil rights and economic development group, has stumped in Iowa, site of the first presidential delegate selection caucuses, and on Thursday headed for Rhode Island. He had scheduled a television appearance there that would be seen in New Hampshire, site of the first Democratic presidential primary next year.

Many members of the ad hoc group say that Jackson is more popular and charismatic than any other possible candidates being mentioned. Jackson says he could raise enough money in enough states to become eligible for federal matching funds.

Moreover, some say, the longer Jackson stays out front as the potential candidate, the more difficult it becomes for the ad hoc group, should it decide to field a candidate, to choose anyone but Jackson.

Yet the same rhyme-laden oratory and independence that has kept Jackson afloat for more than a decade have turned off some potential supporters.

"There is a fear that Jesse doesn't feel accountable to anybody but himself," Rep. Mickey Leland (D-Tex.), one of those involved in the effort, said early this week. "I don't believe that's true, though."

Leland said there also are concerns about whether Jackson, who has never run for office, would be taken as a serious candidate or whether he would be viewed as running "to embellish his ego."

Del. Walter E. Fauntroy (D-D.C.), another key player in the effort, said that Jackson would make a good candidate because he is well known among blacks nationwide and is good at speaking on the issues.

Fauntroy added, however, "The arguments for not projecting him as a candidate are that he is not a politician and in some instances he has alienated politicians in many key districts in the black community. But there's no one in my view who would be perfect."

Fauntroy, D.C. Mayor Marion Barry, Rep. Louis C. Stokes (D-Ohio), Gary, Ind., Mayor Richard G. Hatcher and Atlanta Mayor Andrew Young also have been mentioned as possible candidates. Young has said he is not interested.

Theoretically, the purpose of fielding a black presidential candidate would be to gain leverage at the 1984 Democratic National Convention, influence selection of the nominee and formation of the party platform and prevent the party from taking one of its most loyal voting blocks for granted.

A study by the Joint Center for Political Studies here, however, warned that a black candidacy could divide black leaders and drain support from the Democratic nominee, especially in the South, a key battleground, where black voting strength is greatest.

Young, another member of the ad hoc committee, opposes the idea of fielding a black candidate. He contends that blacks would do better by endorsing various white candidates who are more likely to win and then get inside a new administration. Young is expected to announce his support soon for the current front-runner, former vice president Walter F. Mondale.

California Assembly Speaker Willie L. Brown also is dubious about the black presidential effort.

"It will never materialize. There are too many key blacks already signed on to somebody else's campaign," said Brown, who is supporting Sen. Alan Cranston (D-Calif.). "Too many of the key officials don't see that a black candidate as the tool to being involved in an important way in an ultimate victory. I'm not sure if Jesse's involvement helps the consideration of the idea."

Other members of the ad hoc group said they would not support Jackson under any circumstances but believe that he would run with or without the group's support. One membersaid that rivalry between civil rights leaders and elected officials was one factor that prevented an endorsement.

Some also said there is rivalry among the numerous former lieutenants of the late Martin Luther King Jr. who are in the group: Jackson, Fauntroy, Young and Joseph E. Lowery, president of King's old organization, the Southern Christian Leadership Conference.

Fauntroy said that he thought the chances were "50-50" that a candidate would be fielded, while Lowery emphasized that selecting a candidate was only one option.

Jackson acknowledges the role that some members of the ad hoc group, which has likened itself to a black leadership family, have ascribed to him.

"I'm a member of the family, but I'm a catalyst. I'm not a researcher or a position-paper writer," Jackson said.

"I'm an activist, but I'm not alone . . . . I am not inclined to make a unilateral move because I think it would be counterproductive and ineffective. If the family can get a candidate with the basic three prerequisites and it's not me, I would support that."

Jackson said the three prerequisites are the ability to galvanize large numbers of blacks, to articulate before the media the interests of blacks, Hispanics and the poor, and to interpret issues beyond the confines of race.

"I'm a strong advocate for the position that we must renegotiate the position with the Democratic Party," Jackson said.

"We are investors without equity. We have vast membership without proprietorship, kind of like the Harlem Globetrotters."