Though he held no formal position in his father's government, he was the chief architect of his father's election campaign; his success led his father to continue to turn to him for political advice after his ascension to the presidency. He was pointed to as the leader of the "Sushi set", a group of young officials so-called due to their alleged preference for expensive Japanese cuisine; they were sometimes criticised for their influence on politics. After the collapse of the de la Rúa presidency, Antonio focused his energies on philanthropy and distanced himself from politics, thus marking the end of the influence of the "Sushi Group".
Antonio, who is a lawyer and a bachelor, has been paparazzi fodder since his father arrived at the La Casa Rosada (the Pink House), as the presidential seat in Argentina is called. In 2000, he started dating singer Shakira, in a romance that made headline news all over Latin America. He and Shakira have been seen together at many important events, including visiting with Dominican Republic president Hipólito Mejía. In March 2001, he proposed to her, with future plans to marry.