He and two of his younger brothers, Prince Bertrand and Prince Antônio, have engaged in monarchist proselytism in Brazil. They played major roles during the campaign for the 1993 plebiscite, which represented the first official opportunity for a return of the monarchy to Brazil since the Proclamation of the Republic in 1889. In it, the people were asked to choose which form of government, presidential or parliamentary, and which form of state organization, republic or constitutional monarchy, Brazil should have. The monarchist cause was not successful, receiving 13.2% of the vote against 66% for the republic.