Everybody got into the act last night, from the president dancing cheek-to-cheek with his wife to the cast taking turns twirling Amy Carter around the dance floor. But hovering like Banquo's ghost over the White House salute to the musical "West Side Story" was the gloomy spirit of ABSCAM.

Nobody wanted to talk about it very much.

Even as congressional leaders promised to investigate allegations of bribery against eight of their members arising from the FBI's "sting" operation, politicians at the White House party were steering clear of anything than might remotely be called an opinion.

"I'd rather not comment on it," said the president's chief congressional liaison, Frank Moore, of the mood prevailing on Capitol Hill.

"I don't know anything about it except what I read in the newspapers," said President Carter.

Attorney General Benjamin Civiletti, one of half a dozen Cabinet officers among the 205 invited guests, said there had been no need to tell the president. "No indictments were being made," he said.

Yesterday morning Civiletti ordered an investigation of whether Justice Department employes had broken any rules in connection with the news leaks on the operation. "I don't fault newspaper people for doing their job," he said last night, "but it is of concern if anyone in the department breaks his ethical or regular code." He pointed out the risk of anybody being "severely wounded or crippled by the publicity."

The attorney general said he did not think the "ruse" of impersonating Arab Shelks and businessmen "has any reflection on the people any more than they had been truck drivers or stockbrokers, which we've used on occasion. The FBI decided upon it two years ago."

President Carter seemed anxious to set aside the weightier problems of state, however, when he introduced the "West Side Story" cast in the East Room earlier. "This," he said of the musical which first opened 23 years ago, "is an evening for pure enjoyment."

Among those enjoying it most were a Chicago couple whose invitation was a reward for their volunteer efforts in helping organize the Carter-Mondale fund-raising dinner in December. When their invitation to the White House party arrived recently, Chicago attorney Robert L. Fogel said he called up Midwest fund-raising coordinator Steve Kersey.

"I said, 'You won't believe what I got in the mail,' and Steve said, 'I know -- I only had four spots [invitations] for 12 Midwest states,'" said Fogel.

White House Press Secretary Jody Powell said the party, however, was "not really" a campaign event. "You've got some folks here involved in it but there are lots of business tyhpes, Georgia friends. At my table were the chairmen of Aetna Life Insurance and Braniff Airways and the head of the American Legion."

Asked who was picking up the tab for the evening -- the White House or the Carter-Mondale Committee -- Powell said: "It's a social occasion -- you can invite who you want."

That included former Washington Redskin Ray Schoenke, co-chairing with Eden Rafshoon the Carter-Mondale artists and athletes committee.

"We're doing pretty good -- fact is, we're doing great," said the former Kennedy family intimate whose lists of jazz performing arts and country music stars supporting Carter have been announced while those of athletes and movie stars are to come later . . "We're staging things according to what we think is the right timing."

The Carters shared front-row seats at a performance of eight musical numbers from "West Side Story" with director-choreographer Jerome Robbins, the only member of the show's collaborating quartet able to make the party.

White House Social Secretary Gretchen Poston said Arthur Laurents, Leonard Bernstein and Stephen Sondheim had also been invited but regretted because of prior commitments.

We could only do it on a Monday because that's the only night the cast wasn't performing," Poston said.

The show ended Sunday at the Kennedy Center and moves to Broadway later this week. Original backer Roger Stevens said that while the musical more than paid its own way through the years, another of his productions, "Mary, Mary," made him more money.

"West Side Story's" Kennedy Center revival, "without a star or anything," wound up $20,000 to the good. "If we'd had a star," said Stevens, "we wouldn't have made any money at all."

Guests saw the show first, then went through buffet lines for a late supper of roast beef. The president led the way and, before he knew it, found himself engaged in an impromptu news conference on these topics:

The draft -- "I haven't decided anything -- no one knows what I've decided." He had not told Rosalyn Carter, he said, although "she might think she knows."

Andrew Young -- "I saw him on television. He's not going [to Iran] as a nemissary of the government."

Muhammad Ali in Tanzania -- "He hasn't changed his mind [favoring an Olympic boycott]. I saw him on television and it was like a challenge saying, 'You prove I'm wrong."

Interception of Brezezinski's jet over the Gulf of Oman -- "I heard it was an F14 -- we don't know if it was an Iranian plane or our own. We don't have any doubt some of them can fly, but whether they're completely operational, well, they're so complicated."

Carter circulated among the tables that had been set up throughout the Mansion's public rooms. The 44 cast members pulled out concealed cameras to grab shots of each other, arms flung around their pal, the president.

Then came the dancing. And after the Carters did a turn to "I Could Have Danced All Night," Nancy Butchko, a swing dancer in the chorus, tapped Carter on the shoulder. "I've been dying to meet you," she told him, cooing later: "A wonderful dancer."

Amy's partners were Jim Mellon, who plays "Riff," followed by Jake Turner, who plays "Gladhand."

"Very amiable," said Turner. "She said, 'You dance faster than he does' [meaning Mellon] and I said, 'I'm younger.'"