In the wee hours of Sunday morning, long after President and Mrs. Carter had left the Congressional Black Caucus dinner, long after Sen. Edward Kennedy (D-Mass.) and Rep. Parren Mitchell (D-Md.) had stirred the 8,000 people in two hotels, Stevie Wonder took the stage.

And, it was generally agreed, Wonder not only stole the show musically, but politically. The question of economic equality and the administration's support of the Humphrey-Hawkins fullemployment act had caused a public clash between Carter and the caucus last week.They made up, Carter conceding.

But Wonder said what everyone else was too polite to say.

"In 1963, 4 percent (the unemployment goal of the bill) ain't good enough. For a country that's the richest country in the world - 4 percent," said Wonder, playing a ballad on the electric piano. "The word that I would call, that's the thing I call bull . . ."

The audience at the most prestigious black political came alive in the pre-dawn session. Indeed, they had cheered President Carter, especially his calling of "brothers and sisters" and his supportive words for U.N. Ambassador Andrew Young, but later they grumbled. With Wonder the message was clear. Complacency has never made heroes.

Since the Congressional Black Caucus, the all-Democratic contingent of 16 blacks in the House of Representatives, started fund-raising dinners eight years ago, the event has multiplied eight times in size. Its tone has fluctuated between a serious social event and productive strategy sessions and has now become a quasi-convention with many moods and faces.

A logistics logjam added to Saturday night's madness this year. Besides the traditional hub of the Washington Hilton, known affectionately last weekend as the Booker T. Washington Hilton, the caucus added the Shoreham-Americana ballroom for the $125-a-plate dinner. Events between the two hotels were transmitted via closed-circuit television, with ABC anchorman Max Robinson and actor Brock Peters as the emcees.

The Washington Hilton location, however, has a certain cachet. That was where Carter spoke and Wonder sang. In the audience were actress Cicely Tyson, composer and singer Curtis Mayfield, Reps. Lindy Boggs (D-La.) and John Brademas (D-Ind.), comedian Dick Gregory and civil right leaders, Vernon Jordan, Jesse Jackson and Coretta Scott King.

Early in the evening Natalie Cole and Shirley Caesar sang at the Shoreham, where the audience included Young, Sen. Edward Kennedy, Democratic National Committee deputy chairman Ben Brown, and eight of the 16 caucus members.

By the time Wonder finished his two-hour show at 3 a.m., thousands of people were wandering through the halls, one group snaking its way to the after-parties, singing Wonder's closing chart, "Ain't nothing wrong with getting down, if you're got somebody to love."

It had been a tense week for the caucus and the president at the White House on Tuesday. President Carter, Vice President Walter Mondale and several caucus members fought, disagreeing on strategy for some of the caucus goals. Rep. John Conyers (D-Mich.) stormed out of the meeting and eventually boycotted the dinner.

By Friday, Carter had invited the caucus back for a 20-minute talk, smoothed things out, pledged action on the full-employment legislation, and sent Conyers a photograph of himself, calling Conyers "a loyal Democrat." When he arrived at the dinner, Carter praised the evening's honorees, black ministers from all over the country, and ran down a list of his administration's positions and black appointments.

In his encore appearance at the dinner, Carter abandoned the standup comic routine he used last year. He also brought Rosa Parks, the seamstress whose refusal to sit in the back of the bus led to the historic Montgomery, Ala., bus boycott, calling her "the mother of the movement." His somber mood apparently scored some points with the predominently black audience that still feels the administration has shortchanged the pivotal black vote of 1976.

After the speech, Rep. Cardiss Collins (D-Ill.) shrugged her reaction. In the bar some out-of-town politicians muttered about "black folks who like to applaud." But Carter had the crowd shouting. Borrowing from the rhetoric style of southern Baptist preachers, he ended up with a call-and-shout session. "Can we afford to be satisfied when thousands of black men are walking the streets without a job?" he asked.

"No!" responded the audience.

For Rep. Charles Diggs (D-Mich.), the senior black member of the House, last week must have been the worst of his public life. His trial for alleged payroll kickbacks had started, but the Diggs circulating the open receptions was relaxed, outgoing and spirited.

Wiley Branton, dean of Howard University Law School, gave him a reassuring tap as he passed. "People coming by, saying a few words, gives the congressman a source of moral strength," said Washington physician Edward Mazique at an adjunct Friday night fund-raiser for Digg's legal fees.

Andy Young, table-hopping around the Shoreham tennis courts in a navy-blue jogging suit, was boasting about the "10 years" of victories at mixed doubles he and Assistant to the President Hamilton Jordan, had culled. Jordan, dressed in white shorts and entered with Young at the caucus tennis tournament, looked puzzled. "We've only played twice in this tournament, Andy," corrected Jordan. Young answered loud enough for their opponents to hear, "We've got to try the Muhammad Ali approach to break down their defenses. You're the strategist, I'm the spokesman."

The list of suite was endless.

Nike Sports Equipment tossed a reception for the champion Washington Bullets and the caucus. Not a bullet or congressperson was in sight, but the room heaved with 200 voices shouting the latest disco chant, "Freak, freak, freak, D.C."

Next door, balladeer Oscar Brown Jr. was performing at the Input-Output Computer Services party for the staff of caucus members. Julian Dixon, a Washington-born politician who is running for Yvonnt Burke's seat, was circulating. Yvonne Greene of Walter Fauntroy's staff headed straight toward the sumptuous buffet, summing up the work of the Hill aide: "Our work load never ceases."

In the upper reaches of the Hilton, the "Friends of Nigeria" had "uniformed security guards checking invitations against a guest list.

"Last year this wasn't organized. We ended up with thousands," said Isyaku Ibrahim, a Nigerian businessman. "This time we wanted to have the right mix of distinguished and respected black Americans. Behind him in a three-room suite, where the earsplitting phonograph music was regulated by a disc jockey, were Rep. Charles Rangel (D-N.Y.), Assistant Secretary of Labor Ernie Green and Valeri Pinson of the White House congressional liaison office.

Very visible during the entire weekend was Marion Barry, Democratic nominee for mayor of the District. Barry handed out small white calling cards for his own party, which coincided, unfortunately, with the Wonder concert.

For three hours on Friday night, Sen. Robert Dole (R-Kan.) circulated the caucus reception, speaking to everyone and pausing for television interviews.

"Well, where are Art Fletcher, George Haley and Sam Jackson?" asked Dole, mentioning three prominent black Republicans from Washington. Since Jesse Jackson said, "Give the GOP a try" earlier this year, Dole said, "We are making a little headway. Certainly we have to come up from 8 percent. If there was any message in 1976, it was that the image of the Republicans and black Americans is not very good." And then he turned to a waiting hand of a Kansas City Democrat.

With his long, beaded braids hidden in a pyramid-shaped cap, Stevie Wonder rehearsed.

As the hotel personnel set the tables, the glasses seemed to have an extra click.

A floor sweeper, the kind of black man Carter, Mitchell and Wonder would later tell the silk and satin crowd not to forget, never took his eyes off Wonder and sang right along with his hymn to urban drudgery and apathy, "Living for the City:"

"A boy was born in hard-time, Mississippi, surrounded by four walls that ain't so prety. His parents give him love and affection to kep him strong, moving in the right direction."