Answer
Liu Shaoqi's political downfall commenced in 1966, coinciding with the onset of the Cultural Revolution, a tumultuous period marked by widespread social and political upheaval in China. Triggered by Mao Zedong's desire to reassert his authority and purge perceived rivals, Liu, who had held the position of President and was considered a potential successor to Mao, fell victim to accusations of revisionism and disloyalty.