The secretary of the Smithsonian Institution said a short video that was cut from an exhibit at the National Portrait Gallery is a work of art and in a perfect world would still be part of the exhibition on gay themes in art history.
He removed the video about AIDS in November after members of Congress and the Catholic League complained. Church leaders called it sacrilegious because it shows ants crawling on a crucifix.
Critics accused Clough of artistic censorship and some art groups threatened to withhold donations.
During his appearance inside the Millennium Biltmore Hotel in downtown Los Angeles, about 25 protesters marched outside.
The video is now playing in the temporary Museum for Censored Art just outside the Portrait Gallery.