Apparently, Banzer had second thoughts, for by election time the left-wing UDP coalition of former president Hernán Siles was out to a massive lead in the polls, and no amount of rigging could have denied it.
At this point, Banzer annulled the elections, denounced the electoral fraud, and disassociated himself from it altogether, basically blaming Pereda and his closest supporters.
He launched a coup d'état, with the support of many military officers who felt Banzer manipulated the armed forces for his own political ends.
After Banzer was forced to leave the Palacio Quemado in July 1978, Pereda was sworn in as president, although not a constitutional one, since the fraud had been so conspicuous that it was plain to see.
[5] Feeling betrayed by everyone (from Banzer to his co-conspirators in the July 1978 coup d'état), at that point Pereda withdrew from public life and never again participated in politics.