At the national level, Argentina elects a head of state and a legislature. The franchise extends to all citizens aged 16 and over, and voting is mandatory for all those who are between 18 and 70 years of age. The President and the Vice-President are elected in one ballot, for a four-year term, by direct popular vote, using a runoff voting system: a second vote is held if no party wins more than 45% of the votes, or more than 40% with also at least 10 percentage points more than the runner-up. Before the 1995 election, the president and vice-president were both elected by an electoral college. The National Congress has two chambers. The Chamber of Deputies of the Nation has 257 members, elected for a four-year term in each electoral district by proportional representation using the D'Hondt method, with half of the seats renewed every two years in all districts. The Senate of the Nation has 72 members, elected for a six-year term in three-seat constituencies for a six-year term, with two seats awarded to the largest party or coalition and one seat to the second largest party or coalition. One-third of the constituencies are renewed every two years. In 2001 the whole senate was renewed. A quota law lays down that at least a third of the candidates on the ballots presented by each party participating in legislative elections must be women.
Provincial law and constitutions, controlled by provincial legislatures regulate elections at the provincial level and local level. Since the separation of powers applies to provinces as well as the federal government, provincial legislatures and the executive are elected separately. Governors are elected in all provinces. All members of provincial legislatures and territorial jurisdiction legislature are elected. As a matter of convenience and cost-saving, elections for many of these provincial and local offices are held at the same time as the federal presidential elections. There is a handful of provinces, however, that instead hold their elections separately.
