It was not a night to dwell on economic plights. Cadillac limousines lined 17th Street; the sidewalk in front of the Corcoran Gallery was filled with lolling chauffeaurs, and the two diamond-shaped buffet tables resembled Roman feasts from the days of Caesar Augustus.

Ambassador and Mrs. Faisal Alhegelan were celebrating their country's national day. Their country is Saudi Arabia, and economic plights are not things they worry about too much in that oil-rich kingdom.

Everyone invited came, for it's madly chic to be on the Saudi party list these days.

Red Blount, Alabama's millionaire contractor, former Nixon postmaster general and Connally national chairman, was partaking of shrimp. He's up East for several days, holding meetings here, in New York and all points political.

There were senators everywhere: Javits (R-N.Y.), DeCouncini (D-Ariz.), Percy (R-Ill.) and Stone (D-Fla.). Treasury Secretary G. William Miller appeared with his wife, and Rep. Bill Dickinson (R-Ala.), bragged that there are two Saudi royal princes at the Maxwell Air University in his Montgomery, Ala., district.

Church people from every branch of religion made up a sizable contingent of the guests, and their talk ranged all over the spectrum. Dr. Frank Maria of New Hampshire, who represents the Eastern Orthodox Church at the National Council of Churches, made a flat prediction on the outcome of the New Hampshire Democratic primary. "No, it is certainly not too soon to predict a winner," he said. "Kennedy will win."

Asked why he was so certain, he explained that many New Hampshire voters are of Massachusetts origin, "and they are totally establishment people."