Many of the people seated and otherwise jammed into the lofty chandeliered reception room of the Organization of American States weren't even American citizens -- but Jimmy Carter came and gave a speech anyway.

John Richardson, standing quietly in the room, verbally patting Carter on the back, wasn't even a Democrat. And the woman singer in gigantic white plumed headdress and sequined costume who gave the beaming president a big kiss didn't even speak English the whole evening.

The president was hardly campaigning -- at least not in the usual hotel-dinner-for-the-local-party-members sense.

"Gracious no," said Wayne Smith, the very gracious, fluent-Portuguese-speaking Presbyterian minister who more or less presided over all this last night. "Who's going to vote for him who's here tonight?"

Nonetheless, Carter and his wife, Rosalynn, attended the gathering of about 600 hosted by an Atlanta-based foreign-exchange program, the Friendship Force, to which the Carters have been rather like godparents since it started in 1977.

And they didn't just buzz in and buzz out -- they came in, sat through a few speeches, gave a couple of their own (one each, first lady followed by the president) and then settled down in the first row next to Helga Orfila and her husband, Alejandro Orfila, secretary general of the OAS, for at least half an hour of entertainment by a Brazilian singer named Rosemary, then more music by a Colombian group called Los Bunkers.

They stayed for more than an hour.

"I believe that people -- ordinary citizens -- can play an important role in improving relations between countries," said Rosalynn Carter, talking about the exchange program before introducing the president, whom she called "a good friend of Brazil a good friend of Columbia and a good friend of all the Latin American countries."

President Carter said of the Friendship Force, "I believe it will be looked upon as one of the great new ideas benefiting our country." Carter said people from other countries had come and stayed in the homes of "schoolteachers, friends, farmers, laborers and engineers."

He mentioned too that the Friendship Force -- which is nonprofit and supported by contributions and the fees that the traveling citizens pay for their trips -- was not supported by government funds, which he called a benefit in itself, provoking light laughter.

On stage with the Carters and Smith, who is the head of the Friendship Force, was a Brazilian named Ernesto Pereira Lopez, the former president of the Brazilian Congress who showed the Carters around Brazil when they visited with Smith. That was in 1972, when Carter was governor of Georgia. Carter called Periera Lopez, who had flown in from Brazil, "a truly remarkable man."

"He made us feel at home," said Carter, "when we could have felt embarassed and alone."

To hear Wayne Smith tell the story, Pereira Lopez "opened up his home, had parties for them, got Carter an interview with the president of Brazil -- that was a whole lot better than a governor trooping over with a U.S. ambassador."

Mayor Marion Barry, also there, was sidetracked by a Brazilian woman, Lucia Helena Werneck Porto -- one of 160 Brazilians on a current exchange program, living for two weeks with families from North Carolina and Ohio -- who posed him with some 20 red-jacketed schoolboy members of a soccer club, also here on the program.

"This is a reach-out to friends and neighbors," said Barry. He scanned the sea of American and Latin faces, adding, "There should be more blacks here at affairs like this. If more were told, they might be more interested in coming. But we'll get the word out."