There's surely nothing new about indulging messianic conceits on Capitol Hill. But a dozen or more lawmakers allowed power fantasies to balloon a step too far when they honored invitations to the bizarre self-coronation of the Rev. Sun Myung Moon as Messiah at a Senate reception room last March. News has just leaked of the loony event -- one of scores of usually mundane photo-op toadyings that occupy Washington lawmakers. Now the attendees are fleeing the record of the crowning as if it were a burning building. ''I had no idea,'' said one in post-coronation remorse.

Mr. Moon, an eccentric billionaire, convicted tax cheat, conservative publisher and power broker, grandly donned scarlet robes and a golden crown at the Dirksen Office Building. ''I am God's ambassador, sent to earth with his full authority,'' he announced.

The scene summoned the moment in Robert Graves's ''I, Claudius'' when Emperor Caligula declares himself a god in the Roman Senate; a fawning solon instantly offers a prayer. No lawmaker was reported praying to Mr. Moon, although Representative Danny Davis wore white gloves in presenting the pillow from which Mr. Moon snatched up his crown. Mr. Davis, an Illinois Democrat, later insisted his role was not related to campaign contributions he received from Mr. Moon, but to Mr. Moon's efforts on behalf of world peace.

As they scrambled for cover, politicians said they went to the event because it seemed to involve civic honors for constituents and sponsorship by Mr. Moon's newspaper, The Washington Times. The Messiah motif (and Mr. Moon's news that his teachings had seen Hitler and Stalin, Marx and Lenin ''reborn as new persons'') was an added starter, lawmakers pleaded. So far, as nonbelievers wonder at it all, no lawmaker has dared own up to authorizing use of a Congressional sanctuary for such a ludicrous traducing of self-government.