"We are indisputably the group in America that's the razor's edge," shouted Rep. Cardiss Collins to a cheering, predominantly black audience of 5,000 on Saturday night. And the crowd that made the difference in the presidential election in 1976, and can't wait to move into next year's fray, proved more clearly than ever last weekend that the black body politic is no monolith.

Politically, it was ready to run in at least three directions.

Crying out for black unity, Collins set the first tone of the Congressional Black Caucus' annual fund-raiser by warning, "We will no longer wait for political power to be shared with us, we will take it." The packed crown, sitting in two cavernous halls at the Washington Hilton Hotel, came to its feet.

Five minutes later, Clarence Mitchell, the elder statesman of black politics, pleaded for peaceful coexistence with the White House and was both cheered and booed. "I would have opted for the president to be here," said Mitchell, referring to the caucus' snub, which was not unanimous, of President Carter.

And five minutes after him, Andrew Young, the former U.N. ambassador whose resignation added to the breach between Carter and his black constituency, urged a compromise. "I'm not going to walk away," he said, to moderate applause. "Right now black people in this administration are responsible for $150 billion of a $500 billion budget, and it's going to be there for a year and a half . . . . If you have power, you can renegotiate the contract. I think we lived up to the contract of 1976."

Over the last three days of the Ninth Annual Black Caucus' legislative weekend, which brought 10,000 people to Washington, the focus was on future and present presidential politics, the growing participation of blacks in foreign policy, and a prediction of the 1980s as the worst modern decade for blacks.

Releasing himself from an Alpha fraternity handshake, Maynard Jackson, the mayor of Atlanta, talked of the special mystique of the weekend, its whirl of workshops, receptions and speeches. "It's a homecoming, a period of rejuvenation, a time of political recommitment, a chance to catch up on the latest gossip and a happening. And it couldn't happen for a better cause, because these 17 folk are asked to represent all of black America."

Swirling around Jackson was a non-stop pageantry that indicated the caucus' drawing power: Walter Fauntroy and Joseph Lowery, just back from a controversial trip to the Middle East, were stopped for press conferences every few feet; Jesse Jackson, on his way to the Middle East, had a band of the press behind him; Benjamin Hooks, Patricia Roberts Harris, Ray Marshall, Moon Landrieu, Hamilton Jordan, Larry Pressler, "Sugar Ray" Robinson, Whitman Mayo, Lou Gossett, John Brademas, Bobby Seale and Yvonne Burke all worked their way through the pressing, ear-splitting crowds.

When Clarence Mitchell, the retired NAACP lobbyist whose decades of work on the Hill earned him the title "the 51st senator," was booed, he didn't flinch. "I just want to make it clear that I never run away from that kind of conduct," he said. "And those who want to boo. Boo to my face and I'll meet you in the alley."

Mitchell found himself defending Jimmy Carter, who is often at odds with the Black Caucus and was not invited to speak this year. The welcome for Carter was always warn in past years, though Carter chose to salt his policy points with Carson-like one-liners and a summary of his black appointments. This year the caucus didn't extend the invitation, unofficially indicating that the White House could buy a table, as did Sen. Edward Kennedy, California Gov. Jerry Brown, the Palestinian Liberation Organization and a group from the Israeli embassy, and that he could mingle at any event.

Carter didn't show, although he did hold a reception for black elected women officials and representatives on Friday. But his men were out in full force: Vice President Walter Mondale attended Friday night's dinner-dance, and in the Saturday night crowd were congressional liaison Frank Moore, re-election chairman Evan Dobelle, special assistants Louis Martin, Anne Wexler and Sarah Weddington and OMB director James McIntyre. "We've always supported the Black Caucus," observed White House chief of staff Hamilton Jordan.

Fauntroy, Joseph Lowery and Jesse Jackson were the spotlight stealers of Saturday, providing the only fresh news.

Even Jackson, the most media-conscious of the three preachers, was startled at the press pursuit. Once when he emerged from a meeting, all the cameras started whirling at the same time, sounding like a flock of birds fleeing from a tree. He faced the cameras several times, explaining how the Middle East developments affect black Americans. "If this is a hot war, we will die first. If it is a cold war, we will freeze first."

Not all the attention focused on the three was favorable: some felt that by seizing the Middle East issue, they were detracting from domestic issues. "Yes, there's some tension but it will work out," said Fauntroy. Added Lowery: "We don't need an endorsement. God endorsed us."

"We are going to the sources. We want to know why 30 percent of the gross national product of Israel is committed to defense," said Fauntroy, spilling out five minutes of statistics on the Middle East. "Hey, you really know your stuff," teased a reporter. "I have become an expert," said Fauntroy, laughing.

The weekend wasn't all politics. For a lot of people, it was a chance to parade their new fall wardrobes and check out what everybody else was wearing.

This year, that meant anything and everyrhing -- glittering gowns (black lame and sequins were popular), narrow skirts, mink, beads, feathers, Chinese silk, African jewelry and flowers from orchids to roses to carnations.

The official fashion show was Saturday afternoon, a slick, colorful presentation put on by popular New York fashion consultant Audrey Smaltz. Twenty-five models ranging from fashion superstar Beverly Johnson to Freda Holmes, an ingenue from Washington, put on a sold-out luncheon benefit for 2,700.

Competition to appear in the show, called by some "the launching pad for black models," was rough: Sixty applied for the 25 positions. After Holmes got a message at midnight last week telling her she'd made the show, "I couldn't get back to sleep."

But backstage before the show, Holmes seemed calm as bedlam erupted around her. Smaltz herself appeared in a state of friendly panic.

"You guys finish that pressing," she yelled at two women who were supposed to be ironing the Bill Blasses and Mary McFaddens. "If I see any wrinkles going down the runway, it's going to be you and me, honey." She rummaged furiously through a rack of clothes. "This skirt is an Austin Zuur," she cried. "Now where is the ostrich-feather jacket?"

Beverly Johnson was serene as she touched her toes and stretched her neck. She has made more than $500,000 this year, but the caucus show is a benefit.

"Audrey's kind of special to me, and so is the Black Caucus," she said. "It's one of the most important black events of the year. I was really flattered to be asked."

Political buttons were everywhere. Pictures of Fannie Lou Hammer, the late southern civil rights leader, appeared on the blazers and blouses of those leaving the National Hook-Up for Black Women breakfast on Saturday morning. Coretta Scott King and Christine King Farris, the widow and sister of Martin Luther King Jr., wore "We Support U.S. Ambassador Andy Young" buttons at the White House Friday. But what did the president say? "What could he say?" countered Farris.

The Los Angeles contingent wore "Kennedy-Bradley" buttons, supporting the Massachusetts senator and the Los Angeles mayor for a 1980 presidential ticket; a few in the D.C. crowd, jammed into Mayor Marion Barry's party after Young's speech Saturday night, wore a slightly different version calling for "Kennedy-Barry '80"

Barry for vice president?

"Why not?" said Edna Wolf, executive director of B'nai B'rith Women. "There were people that said a couple of years ago -- 'Barry for mayor?'" But so far, the Barry campaign hasn't gone much past the button stage.

Some glimpses of the famous and not-so-famous at the caucus:

On Friday night, current singing rage Teddy Pendergrass arrived at a CBS Records party, immediately setting off a chain reaction of flashbulbs from the cameras, and kisses from the women. "He reminds me of my husband," said Joy Terrell, who works for the Black Caucus and kissed Pendergrass twice -- once at the party and once on stage after his benefit in the Hilton's ballroom.

In the midst of a pre-dinner reception, Jeanne and Arthur Ashe found themselves in an informal receiving line. Ashe, the tennis star recuperating from a recent heart attack, said he and his wife came to the caucus "because we thought it would make me feel good." Jeanne Moutoussamy Ashe, whose four-minute documentary was shown at the dinner, said "the photography was done by a black woman, the editing was done by a black woman, the doctor who delivered the babies is a black woman, and the babies are black. This seemed the proper place to show it."

During Mayor Barry's Saturday night party, the Rev. Sean McManus, who said he represents 43,000 people as director of the Irish National Caucus, was waiting to meet Jesse Jackson to ask him to take his "quest for nonviolence" to Northern Ireland.

Later on Saturday night, National Urban Coalition president Carl Holman headed for his Southwest Washington home and gave his Hilton hotel room to Gary, Ind., Mayor Richard Hatcher. Hatcher got telephone calls all night for Holman, and at 4:30 a.m., a pop-in visit from Dick Gregory. The comedian was dropping off "eucalyptus pills or something," according to Holman, for Holman's bad back. Gregory ended up camping out in a chair and analyzing the caucus weekend with Atcher until almost dawn.

The same night, National Urban League president Vernon Jordan was acting a little testy. When a reporter stuck a microphone in Jordan's face and asked, "What do you think of the Jewish-black rift?" the league president snapped: "We have had a dispute. I have disputes with my wife, but we don't get divorced. It would be unwise for Jewish and black America to get divorced."

On Sunday morning during a crowded brunch at Holman's house, Jordan was calmer. "Don't ask me any questions," he said. "I just got out of bed. My brain is scrambled this morning."

Every year, as the politicians and their supporters stand around the hospitality suites of the large corporations that buy tables and throw parties -- this year Avon Products, Phillip Morris, American Airlines, AT&T -- and scores of other parties, the talk turns to accomplishments of this million dollar weekend.

Why does it seem that the politics gets sidelined for the partying, some people asked -- especially this year with the presidential election right around the corner, splintered politics and a dismal economic forecast. The need for beefing up the agenda was clearly evident in the heated discussions about a black political convention.

"There's almost unanimous agreement a black political convention should be explored," said Eddie Williams, the president of the Joint Center, after a closed-door session. "But the feeling is that this meeting is for information. There's a lot of work before we can have a convention."

"We served in excess of 10,000 meals today," said a relaxed head Hilton chef, winding down with a Budweiser and broiled lobster after Saturday night's dinner of 4,800 Cornish game hens, 2,500 pounds of broccoli, 2,500 pounds of baby Belgian carrots and 500 raspberry souffles.

"Relatively easy," he insisted. "No problems, except I need a shower badly." Hilton Hotels took in $87,500 for the 5,000-person dinner, not including wine and extras.

And that was just a small portion of the money that changed hands during the weekend. Several hundred thousand dollars, at least, flowed in the course of two mammoth dinners and several luncheons and breakfasts.

In fact, the caucus has become so large that there was talk this year of moving it to a bigger city, say New York, in 1980. "Washington just can't accomodate the people," said Alma Rangel, wife of the caucus member from Harlem.

Mayor Barry's reaction was swift. "We're not going to allow that to happen," he said.