Paz Estenssoro nonetheless ran for president in 1947, earning 3rd place, and again in 1951, when the MNR surprisingly won the electoral contest, despite the fact that the laws of that time confined the vote to a small, propertied stratum of the citizenry.

The elections, however, were unilaterally annulled by the ultra-conservative government of Mamerto Urriolagoitía, and the MNR at that point went underground, coming to power after a popular national revolution the next year.

During the Hernán Siles administration, the MNR began to polarize and fragment, with a conservative wing led by Wálter Guevara and an increasingly assertive left-leaning faction commanded by the charismatic COB leader Lechín.

His choice as vice-presidential running mate was the increasingly hard-to-manage Juan Lechín, an action that prompted the defection from the MNR of Wálter Guevara, who felt he had been stepped over.

Traditionally, attempts such as these (known as "prorroguismo") have been strongly condemned by the Bolivian political elites, many of whose members may have been waiting for their turn to occupy the presidential palace for years.

To symbolize Paz's steady rightward drift, he chose the charismatic commander of the Bolivian Air Force, General René Barrientos, as his running mate.

To be fair, Paz's increased reliance on the armed forces was to some extent influenced by Washington's constant demands that the military be fully reconstituted and equipped to fight possible Cuban-style Communist insurgencies.

In any case, the René Barrientos choice was a final act of folly, as Paz did not seem to have noticed the deep resentment of the outwardly loyal commanders of the "new, revolutionary" military toward the MNR's manipulation of the armed forces for political ends.

Partisan intransigences prevailed and the latter could not agree on any of the candidates, eventually settling on naming as provisional President the head of the senate, Wálter Guevara, then in alliance with Paz's MNR.

[3] Up until the economic restructuring was announced, Paz and his planning team had not informed the rest of his cabinet or the public of the direction in which they were moving, knowing that it would be met with mass protest and strike action.

In the months following the announcement of Decree 21060, a curfew was imposed on citizens, travel throughout the country restricted, universities and opposition meetings were raided, and hundreds of union leaders were kidnapped and taken to prison camps in the Amazon until strikes were called off.

[4] The readjustment policies—conducted to a large extent by Paz Estenssoro's vigorous Minister of Planning, Gonzalo Sánchez de Lozada, who was later to serve as President of Bolivia—came to be known as the New Economic Policy (NEP).

[5] However, Bolivia remained the poorest country in South America and anti neo-liberal forces began to grow as a result of his liberal economic policies leading to the election of socialist Evo Morales in 2005.