Combining a broad spectrum of ideological opinion from revolutionary Marxism to Liberation theology and reformist agendas of broadened peasant proprietorship, Sandinismo commanded widespread support within Nicaragua and overseas. The Sandinistas replaced the Somoza dictatorship with a broad-baced coalition government that was expected to be an interim replacement until elections could be held.
Rival conflicts quickly dogged the group, however and the coalition split up. Daniel Ortega and his more radical socialist supporters soon gained complete control of Nicaragua's government, while other more conservative members, such as Violeta Barrios de Chamorro were either expelled or resigned from the council and formed their own political groups. Allegations spread among critics that the Ortega clique were planning to turn Nicaragua into a Communist state like neighbouring Cuba, a country which many of Ortega's supporters admired. Such fears were accentuated by the Sandistina Government's attempts to crack down on political dissent, especially within Nicaraguan media outlets.
The Sandinista government began to openly challenge economic interests of the United States in the region. Ortega also began to appeal for economic and military aid from the Soviet Union and Cuba, and began supporting leftist revolutionaries in war-torn El Salvador, prompting much fear in Washington.
As in Castro’s Cuba, the Sandinistas immediately set up neighborhood associations as local spy networks for the government. Each neighborhood had a Comité de Defensa Sandinista (Sandinista Defense Committee), or CDS, and it reported "counter revolutionary" activities to the authorities. In addition to local organization, the local CDS controlled food rations, employment and leisure time.
Thousands of Nicaraguans who attempted to protect their private property, or who committed the new crime of owning private property, were imprisoned, tortured, or executed by their new Sandinistan government.
The Sandinistas enacted a forcible relocation of tens of thousands of Miskito Indians from their land. According to organizations such as Amnesty International, the OAS and United Nations Human Rights Commission, the Sandinistan army committed myriad atrocities against the Indian population, killing and imprisoning approximately 15,000 people. The crimes included not only mass murders of natives themselves, but according to the United Nations Human Rights Commission a calculated liquidation of their entire leadership. Miskito Contras were organized with other Indians in the Misurasata.
According to the Nicaraguan Commission of Jurists, the Sandinistas carried out over 8,000 political executions within three years of the revolution. The number of "anti-revolutionary" Nicaraguans who had "disappeared" in Sandinista hands or had died "trying to escape" were numbered in the thousands. By 1983, the number of political prisoners in the Nicaraguan jails were estimated at 20,000.
According to Amnesty International, political prisoners in Sandinista prisons, such as in Las Tejas, were consistently beaten, deprived of sleep and tortured with electric shocks. They were routinely denied food and water and kept in dark cubicles that had a surface of less than one square meter, known as chiquitas (little ones). These cubicles were too small to sit up in, were completely dark and had no sanitation and almost no ventilation
The US government soon began to sponsor anti-Sandinista "Contra" (counter-revolutionary) terrorist groups supported from bases in neighbouring Honduras. This caused a great deal of controversy both within the United States and the rest of the world, and prompted much debate on the extent to which the US should interfere in foreign nations' governments. (See also Iran-Contra Affair.)
Edén Pastora (Comandante Cero), a former Sandinista leader, formed a Contra group of his own. There were many violent conflicts between the rival guerrilla groups, leading to a civil war.
As part of a peace settlement, Ortega agreed to hold elections. The Sandinistas were voted out on 26 February, 1990 in favor of a 14-party alliance led by Violeta Barrios de Chamorro, who had become one of the leading anti-Sandinista advocates.
After their loss, some of the Sandinista leaders held part of the property that had been nationalized by the FSLN government. This process has been named piñata and was tolerated by the new government.