"Where's Liza?" became the call of the elegant guests and overanxious press careening through the White House staterooms Saturday, several hours before "Festival at Ford's," the theater's 7th annual fund-raising gala.

Ben Vereen. Lou Rawls. Natalia Makarova. Attorney General William French Smith. An avalanche of shrimp.

But no Liza Minnelli.

Mark Gero, her husband and manager, explained why Liza didn't make it to the White House reception:

"We had all intentions of going, but she doesn't feel well," Gero said backstage, before the performance. "We just got here this afternoon and we have to leave on the private Lear jet right after the performance . . . "

Minutes later, Minnelli dazzled the glittering audience at Ford's Theatre with her medley of popular songs, concluding with "New York! New York," which she explained at least five times, "was written for me, even though someone else has been singing it lately. A lot!" Everyone laughed.

Minnelli was the shimmering finale to Ford's expensive and tony benefit variety show. The president and first lady traditionally attend the show, which is the middle of the long, three-part event that begins with 5 o'clock White House cocktails and ends with fancy veal at midnight at the Organization of American States.

After a series of false starts and numerous problems revolving around this year's benefit, the show brought in $250,000. Tickets ranged from $250 to $5,000. Last year, $400,000 was raised for the theater.

"It was harder to sell tickets this year," said Frankie Hewitt, Ford's producer. "And we just couldn't get it together . . . "

President Reagan took the opportunity to pitch for private support of the arts in his remarks following the show.

"We support theaters, opera, concerts . . . through private contributions more than the rest of the world together," he said.

"I'm here to preserve the arts," Vereen said later. "We were upset about the budget cuts last year, but now it's time to stop depending on the government. We have to support our own . . . We have to leave something for our children."

The evening took on a remarkable resemblance to Reagan's inaugural, although it was still too warm for mink. Long limos knotted downtown traffic for hours and the air smelled like the perfume counter at Bergdorf-Goodman. Opium! Oscar! Joy!

Inside, comic juggler Michael Davis stole the show. He started off with one little orange ball and moved on to juggling a knife, an ax and a meat cleaver. He was extremely close to the president

"I will now juggle these razor-sharp instruments to amuse the people in the back -- the Democrats," said Davis to a chorus of guffaws.

"Now you're not laughing anymore," he joked to Reagan. "Don't worry. I've done this before. Twice."

Later Davis said that the Secret Service had checked all the implements "to make sure they weren't going to explode . . . and they told me not to stand too close to the edge of the stage.

"I didn't think they were going to let me do it at all. I thought for sure they would nix it during rehearsal."

Afterward, guests were still lauding his performance, which ended when he bit into an an egg that he was juggling. He was the unanimous favorite of the show. Well, almost unanimous.

"You really want to know who I thought was the best?" said Jerry Zipkin, the decorator and close friend of the Reagans who redid the White House living quarters. "The president. The juggler was good too. But the president. He was the best, marvelous."