The vote was annulled, however, due to the discovery of massive fraud on behalf of the government endorsed candidate, General Juan Pereda.
They, too, proved inconclusive, as the UDP's Hernán Siles Zuazo, with Paz Zamora as his vice-presidential running mate, finished first at the ballot box, but without attaining the 50% majority necessary for direct election.
Eventually, Congress proclaimed as temporary President the head of the Senate, Dr. Wálter Guevara, pending the calling of yet a new round of elections in 1980.
During the 1980 elections, the ultra-right wing of the Bolivian military began to intimate that it would never stand for the installation in the Palacio Quemado of the "extremist" Siles and Paz Zamora.
Siles Zuazo and Paz Zamora fled to exile, but returned in 1982, when the military's experiment had run its course and the Bolivian economy was on the verge of collapse.
At this point, the MIR (led by Paz Zamora) disassociated itself from the regime (1984), deserting the UDP's sinking ship when Siles' popularity sank to an all-time low.