After Bolivia's disastrous defeat in the conflict, he became convinced that the country needed profound structural changes and supported the progressive Military Socialist regimes of David Toro and Germán Busch.

Following Busch's suicide in August 1939, conservative forces reasserted themselves, took power, and won the 1940 elections in which the traditional parties linked to the country's big mining interests triumphed at the polls with General Enrique Peñaranda.

Villarroel became a member of RADEPA (Razón de Patria, or Fatherland's Cause), an open-military faction of young officers founded in 1934 by Bolivian prisoners of war in Paraguay.

It sought mass support, backed military intervention in politics, and hoped to prevent excessive foreign control over Bolivia's natural resources.

"[6] Villarroel was allowed to take residence in the Palacio Quemado as de facto president while members of the MNR, including Paz Estenssoro, took various positions in his cabinet.

[10] The newly installed Villarroel government within hours of its assumption to power sought to reassure the U.S. of its desire for good relations and support of the war effort.

Hence, Villarroel's government committed to negotiations over the exclusive sale of quinine, the nationalization of German and Japanese companies, and a new tin contract at hopefully higher prices.

[10] Despite their efforts, the view by the U.S. that Villarroel and the MNR were, in fact, a pro-fascist regime resulted in Secretary of State Cordell Hull issuing a memorandum on 10 January describing their pro-Axis sympathies.

"[12] Under the mounting weight of U.S. pressure, the remaining MNR ministers, Víctor Paz Estenssoro, Rafael Otazo, and Wálter Guevara resigned on 5 April 1944.

[17] Not long after, on the initiative of peasant leaders such as Francisco Chipana Ramos, the president agreed to sponsor a fully indigenous congress to be held in early 1945.

The emphasis by the press on the "authentic native" dress, language and rural labor, marked the indigenous peoples as a distinct group within the Bolivian nation.

[17] Though he worked closely with Villarroel's government during the congress, Chipana presented the event as controlled by the delegates themselves while sidelining more radical demands for redistribution of the land.

Despite this, the conservative landlords refused to accept even Villarroel's moderate changes to the labor regime, but ongoing indigenous peasant mobilization would enforce the new laws.

Allegedly among these repressions was the attempted assassination of José Antonio Arze, a prominent Bolivian sociologist and Marxist and head of the Revolutionary Left Party (PIR).

While Arze had initially presented his sympathy for the 1943 coup, he refused to supply the Villarroel regime with civil support from the PIR unless the new government got rid of "fascist" elements.

The attempt on the life of the influential leftist politician was a cause of grave concern among academics which, given the previous animosity between the two, suspected government involvement in the incident.

In an attempt to push against this notion, a government delegation including Villarroel himself, accompanied by Foreign Minister Enrique Baldivieso, visited Arze at his hospital, showing concern for his health.

The initial decision to eliminate him was reversed due to international pressure and the intervention of diplomatic representatives of Argentina, Chile, and the United States which ultimately secured Hochschild's release on 15 August.

The rest, two senators: Luis Calvo and Félix Capriles; two former ministers of state: Carlos Salinas Aramayo and Rubén Terrazas; and a military man: General Demetrio Ramos were executed near Chuspipata.

In 1977, writer Roberto Querejazu would claim that "if the Catavi massacre was the flag raised by the MNR and the RADEPA in their revolt against Peñaranda, the 'crimes of Challacollo and Chuspipata' became those of the PIR and the traditional parties to drag public opinion against Villarroel.

[30] On 17 July, the windows of the UMSA were found destroyed, having been stoned the night before by drunk MNR members including the minister of agriculture, Julio Zuazo Cuenca.

During one of these rallies, Bergel Camberos, a student from the Pedro Domingo Murillo Industrial School, was shot by police, heightening the crowd's animosity against the government.

In an attempt to deescalate the situation, Villarroel met with Héctor Ormachea, the rector of the UMSA, and ordered that the students arrested in the clashes be released.

[29]At 11 p.m., military commanders led by Minister General Rodríguez entered the Palace of Government (the so-called Palacio Quemado) and requested the resignation of President Gualberto Villarroel to avoid a massacre.

While some officers loyal to Villarroel implored against such a decision, it was concluded that it would be difficult to maintain the president's situation without the full support of the army, taking into account that many of the troops who were quartered had relatives who had died in previous clashes.

The jail was attacked and political prisoners released, while Max Toledo, Director General of Transit and member of RADEPA, was surprised and killed in the vicinity of Plaza San Pedro.

There are several accounts of what happened next: One claims that one of the revolutionaries fired his submachine gun through the closed cupboard door upon hearing a noise and discovered the mortally wounded body of Villarroel when he opened it.

The same fates were found within the vicinity of the surrounding streets by Captain Waldo Ballivián, the president's secretary Luis Uría de la Oliva, and the journalist Roberto Hinojosa.