Elections in Mexico are held every 6 years to elect a president and every 3 years to elect a legislature. These elections determine who, on the national level, takes the position of the head of state – the president – as well as the legislature. Federal Level The federal government of Mexico is made up of three branches of government: the executive, legislative, and judicial branches. The executive branch is headed by the president who is also the chief of state and of the army. The legislative branch consists of the Congress of the Union and is divided into an upper and lower chamber. The judicial branch is headed by the Supreme Court of Justice of the Nation and does not participate in federal elections. Executive branch The president of Mexico is elected for a six-year term by direct election of the population. The candidate who wins a plurality of votes is elected president. No president can serve more than a single term in office, therefore every presidential election in Mexico is a non-incumbent election. Mexico does not have an office of vice president. Eligibility Candidates for president must be at least 35 years old. They must be Mexican citizens by birth, as must one of their parents. They must have been residents of Mexico for at least 20 years. They also cannot have been either the governor of a state or the chief of government of Mexico City for six months prior to the election. Legislative branch The lawmaking authority of Mexico is vested in the Congress of the Union (Congreso de la Unión) which is composed of two chambers. Chamber of Deputies The Chamber of Deputies (Cámara de Diputados) has 500 members, elected for a three-year term. 300 deputies are elected in single-seat constituencies by plurality. The constituencies are divided among the 32 states based on population. The remaining 200 deputies are elected by proportional representation in five multi-state, 40-seat constituencies. To be eligible to place candidates in the multi-seat districts a party must have candidates in at least 200 of the 300 single-seat districts and must win at least 2% of the vote in those elections. The 200 PR-seats are distributed based on the percentage of the total national votes earned by each party without taking into account the 300 plurality-seats (parallel voting). However, since 1996, a party cannot get more seats overall than 8% above its