Xenon: Donna Summer singing "Do It Me Right," flashing lights, Roberta Flack, Loretta Lynn, and Jimmy Carter's lieutenants right there in the front row. And from their point of view, the president's speech to the convention last night was terrific.

"I thought it was a good speech," said press secretary Jody Powell. "I thought it was a great speech until I came back and heard the network commentators p...ing all over it. Simple-minded bastards."

Along the same lines, the Carter people collected at the disco didn't think Ted Kennedy was disappointing at all. "The media nitpicks everything," said Hamilton Jordan, who had a beer in the first row of tables. "He endorsed the president yesterday, he appeared on the podium tonight. We couldn't have asked for anything better."

But others thought differently. "He wasn't as outgoing as he usually is," said Kentucky Gov. John Y. Brown of Kennedy's podium appearance. "I'm sure that's a strange scene for him to be in. He looked a little uncomfortable."

Added Brown's wife Phyllis George: "I guess it's hard for him for one night to turn it off."

The Carter/Mondale victory celebration at Xenon didn't even begin till 1 a.m., but a crowd had collected early outside the 43rd Street disco, and in a sytle reminiscent of Studio 54, beautifully dressed bouncers behind velvet ropes kept the undesirables from the desirables. Cameras popped, police were crawling everywhere and the rumors raced -- the president was going to show up, no he wasn't, well, maybe he was. But by 1:30 a good three dozen police were standing in front of the barricades with nothing to do.

Inside the dark, cavernous place with black columns, a black rug and a giant wooden dance floor, the mood was like a victory dance after the football game. This team had won, and its players turned out to dance: Nathan Landow, Smith and Vicki Bagley, who've been everywhere this week, Atlanta Mayor Maynard Jackson, and Tom T. Hall, the singer, Carter supporter and close friend of brother Billy.

Everyone wore the kind of clothes you can see walking down K Street at lunchtime; dark business suits and conservative dresses that were only slightly wrinkled by the heat. It was easy to spot the New York disco crowd with their black leather pants, mini lame dresses and David Bowie haircuts.

And then there was author Fran Lebowitz, who came preppy style in faded straight-leg jeans and a navy blue blazer. "I'm a thrill-seeker," she said. "I wanted to look at the clothes."

But is she a Carter supporter?

"Nah," she replied, "I'm a Republican. Really." A Better Show

There were lots of people hanging around outside on the sidewalks surrounding the Plaza Hotel yesterday, among them Transportation Secretary Neil Goldschmidt. He was smoking a cigar after the Democratic victory luncheon, throwing his arm around selected females and generally absorbing the atmosphere.

Then House Speaker Tip O'Neill spied him. "Hey, have you got a cigar?" he asked. Goldschmidt had. "Oh, you're beautiful," said the speaker.

Goldschmidt, in an aside: "It's one of those exploding ones."

O'Neill was whisked away in a limousine, but it didn't blow up.

The lunch itself was attended by hundreds and hundreds of Democrats who paid $500 each to sit under chandeliers nearly as big as Datsuns and listen to the president speak.

"Everybody said we've put on a better show than the Republican," Carter said in his opening remarks. "It's probably because ours didn't have to suffer from the actors' strike." Then he went on to predict doom, doom, doom, for Ronald Reagan in November.

The president was actually late for his speech, which forced O'Neill, his introducer, to ad-lib from the podium. He killed time by telling Irish anecdotes and Reagan jokes. "Every time we hear that Reagan is the candidate of a major American party, he reminds me of a ship in a bottle," he said. "How does it get there?" Light chuckles from the crowd.

At a table somewhere in the Grand Ballroom was Gov. Robert Graham of Florida, who nominated Carter on Wednesday night. He, for one, didn't think it was fair to say that Ted Kennedy was the one who had really ignited this campaign. "In 1960," he explained, "it was clear that John Kennedy was going to be the party's nominee. But Kennedy did not have the emotion of the convention. That belonged to Adlai Stevenson. I think the same kind of difference between where the heart and emotion is and where the head and reality is will come out of this convention."

Most of the lunch guests were the establishment Democrats who invariably turn up at Washington Hilton fund-raisers in the winter. In fact, the only thing different about this scene was that the decor was considerably more ornate (heavy gold curtains, gilt, sprays of chrysanthemums and snapdragons) and that there were New Yorkers herding outside in the street. Most of them had come to see the president, but others were just attracted by the noise behind the police barricade.

And a few found out to late. "Oh, that was the president?" said Martha Taussig, a Long Island housewife who was talking about her diet with Mary Callahan, a Jersey Shore housewife. "I'm so short I couldn't see."

"It wasn't exciting," said Harold Hofmann, an unemployed Manahattanite, who was having organic rice and Perrier on the steps of the Plaza fountain. "I know what he looks like. I see him on TV all the time." Herd at the Statler

The most exotic party seen this week might really be in the New York Statler, headquarters for the press and the DNC. The Statler figures that on the first day of the convention, 30,000 people passed through the lobby.

Here's what you would have heard if you were standing at the foot of the main escalator from 4:10 to 4:40 p.m. yesterday:

"This is like summer camp for journalists."

"You leave people explicit directions for where to meet you, and they screw it up every time."

"Do you know if you can sell buttons here, or do they throw you out?"

"The prices they were charging! I'm a New Yorker and they're not going to get those prices out of me."

"On va au centre de presse etranger pour ieter un coup d'oeil."

"Excuse me, are you information? We're looking for a place to set down our children for a while."

"Onward, through the fog."

"It will all be a memory next week." When It's Hot

The Ethnic Americans for the Reelection of Carter/Mondale just got themselves organized last week, so they had a lot of party-giving to catch up on. Consequently, in room 4831 of the Sheraton Center yesterday, there erupted a noisy celebration.

The Armenians were the official hosts of this party, given for Set Momjian, the national chair of the new committee. Still, not everybody was an Armenian.

"I was born in Vienna and I grew up in Brooklyn," said one guest with a heavy beard and green eyes. "That makes me Ukrainian-Viennese-Brooklynese. hWe have a very small contingent at the convention . . . one."

The main topic of conversation at the party was how hot it was, inside and out Armenians, Brooklynites, etc., wedged into the small hotel suite that had gray rugs, gray furniture and a view of a very gray New York. There were about 50 people there who hacked away at giant chunks of cheese and crackers.

"Warm enough for you?" somebody said.

"Just cooling off," somebody else said, who was sitting in the hall beside the elevator with his drink.

Miss Lillian was supposed to show, but she didn't. Probably she stayed somewhere the air conditioning was working.