constitutions of a number of countries in South America have granted former presidents the right to be senator for life (senador vitalicio), possibly recalling the entirely unelected Senate of Simón Bolívar's theory (see Bolivar's tricameralism). Most of these countries have since excised these provisions as they are increasingly seen as antidemocratic. The Constitution of Paraguay still has such a provision. Former presidents are permitted to speak but not vote. In Venezuela, lifetime Senate seats existed from 1961 to 1999. The former presidents who held this position were: Rómulo Betancourt (1964–1981), Raúl Leoni (1969–1972), Rafael Caldera (1974–1994, 1999), Carlos Andrés Pérez (1979–1989, 1994–1996), Luis Herrera Campins (1984–1999) and Jaime Lusinchi (1989–1999). The Venezuelan Senate was abolished with the 1999 constitution. In Peru, the practice was extant from 1979 to 1993. Francisco Morales Bermúdez, Fernando Belaúnde Terry and Alan García Pérez were the only lifetime senators until the abolition of the senate in 1993 and the introduction of a unicameral parliament. In Chile, under the 1980 Constitution, two ex-presidents have become senators-for-life: Augusto Pinochet Ugarte (1998–2002) and Eduardo Frei Ruiz-Tagle (2000–2006). Pinochet's parliamentary immunity protected him from prosecution for human rights violations until the Chilean Supreme Court revoked it in 2000. The provision was abolished by constitutional reforms in 2005. In Nicaragua, the 1974 Constitution granted lifetime membership in that country's Senate to former presidents of the Republic. Brazil The senators of the Empire of Brazil (1826–1889) were appointed for life by the Emperor from a list of three, indirectly elected, candidates for each constituency. For details, see Senate of Brazil: History. There were about 250 senators of the Empire of Brazil. For the list of senators, see :pt:Lista de senadores do Brasil Somalia While the 1960 constitution of the Somali Republic (1960–1969) did not provide for a senate (the legislature, known as the National Assembly, was unicameral), it did grant lifetime membership in the legislature to ex-presidents of the Republic. Aden Adde was the only person eligible to hold this position. United States During the Constitutional Convention of 1787, New York delegate Alexander Hamilton proposed that all members of the U.S. Senate, which was at time appointed by state legislatures and intended to check the power of the popularly elected House of Representatives, be appointed for life as a safeguard against "amazing violence and turbulence of the democratic spirit." His views did not prevail, and the final U.S. Constitution specified six-year