`I''ve been reading so much about China,` Warhol said. `The only picture they ever have is of Mao Zedong. It''s great. It looks like a silkscreen.` Warhol`s portraits of Chairman Mao coincided with President Nixon`s historic visit to Beijing. Like many of Warhol''s subjects, the Communist leader was a contemporary icon. The official portrait used by Warhol appeared everywhere in China, while American radicals also knew it from the cover of the `Little Red Book`, an anthology of Mao''s quotations.