The President called them his "kinfolk" the other night at the White House barbecue he threw for them. So naturally you wonder what they are like, what light they could throw on their kissing cousin, why they've stuck to him through thick and thin, as they - the 500 Georgians who have been campaigning for Jimmy Carter since 1962 - were wined and dined and feted (at the behest of the White House) in Washington this weekend.

There have been Yahoo-in-Washington stories since the first hayseed congressman hit town, around the dawn of the Republic, so let it be said, first of all, that this is not one of those stories. Second, let it be said that Washington is not so sophisticated a town as we would sometimes like to believe - not so sophisticated, say, that butlers bearing silver trays full of goblets of gin don't step on your toes, or gossip with guests about what Great Lady's party they served last week. Call that democracy, call it El Tacko, but sophistacated it's not.

So. Yes. Among the Peanut Brigade there are people who are given to an eccentric act or two, which is a great Southern tradition along the lines of grits and shrimp for breakfast.

There are some in the Peanut Brigade who might be glimpsed in the wee hours of Saturday night playing catch with their poddle in the lobby of the Washington Hilton. There are some who might arrive at the Moroccan embassay party in their honor wearing a Hefty garbage bag with eye holes - to keep of the rain, to be sure - and with inimitable aplomb actually check the garbage bag with the uniformed, lace-trimmed coat check woman.

There are some who might slip and speak of "colored people." There are soft-spoken ladies who might inquire, confidentially, if one thought that the progressiveness and cleanliness of South Africa did or did not, in fact prove something. There are pillars of the community who with tightening flinty eyes speak of a Baptist God who appears to be extremely angry.

Those are isolated incidences. The majority of the Peanut Brigade speak - yea, just you and I - of ski trips to Aspen of the efficacy of applying Vitamin E to one's wrinkles, and, off the record, of course, just how badly Jimmy Carter is doing in his relations with Congress. They are polite, bright, well-dressed, well-to-do, and tough the way only people who remember Sherman's march to the sea can be tough. Don't laugh.

"If they think the events of the last few weeks will get Jimmy Carter down," said Sam Way a Pulaski County banker, automobile dealer and farmer who has known Jimmy Carter since 1955, "they just don't know him."

"He'd have to be six feet under before they could get him down," said John Hunt, son of the eight-term Asburn, Ga., sherriff and owner of the Stone Mountain Park Authority.

When you get right down to it, they think Jimmy Carter is being persecuted. That he looks "worn . . . old." That Rosalynn is "too skiny." That Jimmy Carter is being Persecuted because he is a Southerner. And they can't understand it.

"There's nothing arrogant about it; it's all hogwash," says Ford Spinks, a Georgia public utilities commissioner, who with seven others signed a note to bankroll Jimmy Carter's 1970 Georgian gubernatorial campaign. He had been asked if it weren't arrogant of the President to have invited former budget director Bert Lance who resigned under pressure, to spend the night at the White House after Thursday's barbecue.

"They're not doing it to persecute Bert. They're doing because they want to persecute Jimmy. Why? He's from the South. He's not a part of the Establishment, the Establishment-governmental-red-tape bureaucracy which normally brings people into power. By 'they,' I'm speaking of those ultrliberal Democrats who are thinking more of themselves than the country.

Spinks is seated on a yellow brocade couch at the Iranian embassy party SaturdayHe says they thinks Carter's energy bill and Panama Canal treaties are "both liberal positions, and to have the liberal positions and to have the liberals up in arms against him proves that there's something more than just a liberal-conservative aspect to the politic game."

Of course there's more to the political game. Little thing- like Rep. Herman Badilo's (D-N-Y.) mot being told Carter was coming to his district - make Congress mad. "To go into a congressman's district and not let him know." says Spinks, who served in the Georgia Senate with Carter, "that's not so good . . . I'd think that's something he could improve on . . . then again, he's the President and doesn't have to account for his comings and goings." There may be just a little secret glint of populist glee in the idea that the Great Egos of Capitol Hill are no longer being massaged by the White House. But even Ford Spinks would rather have Jimmy Carter's energy bill.

Yolande Fox of the 20th century Foxes, was asked to entertain the Peanut Brigade at cocktails Friday night in her extraordinary Georgetown house. Dot Padgett, Carter's deputy assistant protocol officer, who with Mrs. Hamilton Jordan and Rita Johnson organized the weekend's events, said, "We just wanted them to see a Georgetown house. So I called up Yolande and asked her if she would do it, and after she told me all the reasons she couldn't, she called back and said she would."

"Yolande," said Betty Talmadge, the estranged wife of Sen. Herman Talmadge (D-Ga), "is very proud of her Southern heritage." Fox is from Mobile, Ala., and her accent evanesced Southern once again as the evening went on.

Fox had invited her interior decorator, Grant Gamblen: Superlawyer Clark Clifford: F. Scott Fitzgerald's daughter, Scottie Lanahan Smith: and Fox's fiend Cherif Guellal who is writing a political biography of Algerian revolutionary and Black Panthers' hero, Frantz "Wretched of the Earth" Fanon. There were cucumber sandwiches and Andy Warhol's Portrait of Jimmy Carter in the hall.

It was all very cordial. It was Georgetown meets the Georgians. The Washingtonians talked to each other in the living room. The Georgians talked to each other in the dining room.

Ford Spinks and his wife, Ruby Lee, and the rest of his friends from Tifton, Ga., skipped it all and went to dinner at the Sans Souci.

Tricia Lee is PR woman for the Augusta Area Planning and Development Commission. She is blonde, perfumed, wearing a low-cut dress and a smile as starry as the Confderate flag.

Like many in the Peanut Brigade. Tricia Lee went to campaign for Jimmy Carter in the snows of the New Hampshire presidential primary. Some of the Peanut Brigade speaks of never having seen snow until then. Tricia Lee is sitting at Saturday night's Washington Hilton cash bar dance looking - well, fluffy - and telling this story.

"As you know, the mill area is in Manchaster. I remember going up about three flights of stairs in this old rooming house, and knocking on the door and saying 'Hah! Ahm Tricia Lee an' Ahm fum Gawgia an' Ahd lak to talk to yew about mah fren Jimmy Cotta, and this man comes out with a can of beer - you know, the undershirt type - and he says 'Come on in'

"Well you sort of gulped. You're alone, and I'd thought I'd be raped and mutilated and so you say. Jimmy, this is it. The supreme sacrifice,' I walk in and sit down on the sofa ane this guy - he was all unshaven - already had the coffee table full of the brochures. He's not an intellectual, you know, and he picks one of the brochures up and says, 'Tell me about the reorganization of Georgia.' I said to myself. 'This man thinks he can make a difference. And I thought I could too.'"