Presidential aide Stuart Eizenstat was well into a deadly serious discourse on Iranian oil last night when he was interrupted by Buckles the Clown.

"Excuse me, Stu," said Buckles, who warmly handed Jimmy Carter's domestic affairs adviser a yellow balloon-dog.

"Oh, er, ah," said Eizenstat, who smiled a weak thanks, tried successfully to hide the dog down by his side, then continued where he had left off.

"The bite will come," he said meaning American oil shortages caused by Iranian turmoil, "several months hence. Probably in January."

Beneath Eisenstat, at knee level or so, darted hundreds of kids attending a party at the arts and Industries Building of the Smithsonian. The occasion on was to kick off national hearings today and tomorrow for next year's White House Conference on Families a conference aimed at mom, pop and tranquility that has nonetheless seen plenty of infighting. But more on that further down.

The star kid in attendance was Army Carter, representing the first family.

She wore a coordinated plaid blouse, and corduroy skirt, watched Chuckles (no relation to Buckles) and the Clown do tricks, and was absolutely not allowed to talk to the press.

"That's what her mother and father said," explained a Secret Service agent who looked terminally bored watching Chuckles and his tricks.

The party, held for the 400-plus people and their families who are scheduled to testify for the conference, offered Pinot Chardonnay for adults and MacDonald's orange drink for offspring. Everybody ate fancy hors d'oeuvers -- brie cheese, liver pate, etc. Generally, the offspring were impressed with the goings-on. "It's very amazing," said Monica Harris 10, who delicately ate a finger sandwich and admitted that at most parties she attends (like Darrell Hill last summer), the food is more in the pizza and ice cream range.

Other kids watched Punch and Judy fight, stood wide-eyed when a mime rumaged through their hair for fleas, allowed themselves to be dragged through the exhibits by well-meaning adults and retreated in terror and/or embarrassment if approached by reporters.

And at least one party-goer was pretty terrified when she was introduced to Amy Carter. This was Julia Clinger, 13 who wore a plaid skirt, topsiders and braces and flashed a horrifed glance in Amy's direction in lieu of saying hello.

"Well, she was signing an autograph and I really didn't want to bother her," said Clinger. "Like she's so famous and everything. I think she's pretty. Does she wear braces?"

In the adult crowd were several members of Congress as well as Jim Guy Tucker, a former representative from Arkansas who is now chairman of the conference and John Carr, the conference's executive director.

Which brings us to the infighting. Carr, who is from what sociologists call an "intact" family, was the one appointed after a storm of criticism that forced the original director, a divorced woman, to resign.

This was one reason the conference was postponed from this year to next, although some critics have said its date was also changed to avoid the inevitable pre-election conflicts over abortion, homosexuality and welfare.

But now, the conference is set for next summer in three cities and is pursuing its goal of recommending specific changes in government policyy toward the American family.