He garnered 15% of the vote in an election that many considered suspect due to massive state support for the government-endorsed candidate, Hernán Siles Zuazo. FSB lost momentum after the 1959 assassination of Únzaga.
FSB received 15% of the vote in a contentious election that many viewed with skepticism, largely because of the government's significant support for its preferred candidate, Hernán Siles Zuazo. After Únzaga's 1959 murder, FSB's momentum began to dwindle.