Constitutionally, Bolivia is a centralist republic. The constitution of 3 February 1967 (amended in 1994) provides for a representative democracy, with its government divided into an executive branch, a bicameral legislature (a Congress consisting of a Chamber of Deputies and a Senate), and the judiciary.
Bolivia has had a spotty constitutional history. The current constitution is the result of a series of actions begun by the military junta that took control in November 1964. The junta replaced the 1961 constitution with the 1945 constitution, as amended in 1947. At the same time, it retained those sections of the 1961 constitution that dealt with universal suffrage, nationalization of the tin mines, land reform, and compulsory education. The 1967 constitution was further amended to circumscribe the power of militia forces. In practice, the constitution has not been rigorously observed. Coups and states of siege have been frequent. Congress was dissolved by the armed forces from 1969 to 1979 and again between 1980 and 1982. The constitution was amended in 1994 to give more power to the president and recognize indigenous people.
Under the constitution, the president and the vice president are elected by direct popular vote for a four-year term and cannot serve consecutive terms. If no candidate receives a majority in a presidential election, the Congress chooses among the three leading candidates. However, between 1966 and 1978, no presidential elections were held. The president's powers are considerable, and presidential authority often extends beyond the constitution. The president has the prerogative to declare a state of siege and may then rule by decree for 90 days. The Congress consists of 27 senators (three from each department) and 130 deputies. Deputies and senators are elected for five-year terms concurrently with the president. Bolivia utilizes a form of proportional representation to ensure minority representation in the Chamber of Deputies and an incomplete-list system for the Senate. The regular session of Congress lasts for 90 days.
Universal suffrage, with no literacy or property qualifications, was decreed in 1952 for married persons at 18 years and single persons at 21. The constitution includes a bill of rights, which guarantees the right to express ideas freely, petition the government, and obtain a release under a writ of habeas corpus in case of illegal detention.