Elections in Mexico are held every 6 years to elect a president and every 2 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 Union of Congress 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.
The Chamber of Deputies 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. However, since 1996, a party cannot get more seats overall than 8% above its result nationally. There are three exceptions on this rule: first, a party can only lose PR-seats due to this rule ; second, a party can never get more than 300 seats overall ; and third, a party can exceed this 8% rule if it wins the seats in the single-member districts. Deputies may serve up to four consecutive terms.
The Chamber of Senators has 128 members, elected for a six-year term. 96 of these seats are in three-seat constituencies. In these constituencies, two seats are awarded to the party with the most votes and one seat is awarded to the party with the second most votes. The remaining 32 seats are awarded by proportional representation on a nationwide basis. Senators may run for a consecutive term.
Eligibility
Candidates for the Chamber of Senators must be registered voters at least 25 years old. They also must have been born in, or been residents of the states they are running in for at least six months. Electoral magistrates, the Secretary of the Electoral Tribunal, and the Executive Secretary and Executive Director of the INE must separate themselves from their positions for at least three years before seeking legislative office.
State and municipal level
At the local level, each of Mexico's 31 constituent states elects a governor to serve a six-year term; they also elect legislative deputies who sit in state congresses, and municipal presidents ''. Mexico City, the national capital, elects a head of government in lieu of a mayor, city assemblymen in lieu of state congressional deputies, and borough mayors in lieu of municipal mayors.
State of Mexico
Governor
To be a Governor of a state of Mexico:
State-born candidates must have been a resident for three years previous to the election
Mexicans born outside of the state must have been residents for five years previous to the election
Candidates must be at least 30 years old
Candidates cannot have been a minister of any religion for five years previous to the election
Candidates cannot have been in the military or a head of public security forces for 90 days previous to the election
Candidates cannot have citizenship in any country other than Mexico
State legislature
Members of the state legislature are elected to three-year terms. Forty-five seats are apportioned in direct elections in single-member districts and 30 are apportioned via proportional appointments. Political parties nominate their candidates for proportional appointments before the election. For a party to be eligible for proportional-appointment seats they must run candidates in at least 30 districts and receive at least 3% of the vote throughout the state. Deputies can serve up to four consecutive terms. Similar to the federal Chamber of Deputies, a party cannot have more than 8% more seats in the legislature than their percentage of state-wide votes unless that excess was earned in the direct elections. To be a deputy of the legislature:
State-born candidates must have been a resident for one year previous to the election
Mexicans born outside of the state must have been residents for three years previous to the election
Candidates must be at least 21 years old
Candidates cannot have been a minister of any religion for five years previous to the election
Candidates cannot have worked for any election commission for two years previous to the election
Candidates cannot have been a sitting municipal or federal legislator for 90 days previous to the election
Candidates cannot have been a sitting judge for 90 days previous to the election
Candidates cannot have been in the military or a head of public security forces for 90 days previous to the election
Candidates cannot be a sitting governor
Political parties
Mexico has a multi-party system, with three dominant political parties. Prior to 2000 Mexico had a dominant-party system under the Institutional Revolutionary Party, and a number of smaller opposition parties. Alliances and coalitions are common: normally, they are local affairs and involve one of the big three and any number of minor parties, though in extraordinary occasions two of the big three will ally themselves against the third.
Voter eligibility
In order to be able to vote, all Mexican citizens must obtain a photographic voter identification card from the National Electoral Institute. To receive a card, potential voters need:
Proof of either their birth in Mexico or their naturalization
Some form of photo ID
Proof of their residence
With these three documents, a potential voter can request their Credentials to Vote card.
Indigenous communities
Article 2 of the Mexican constitution provides for the self-government of indigenous communities according to their 'traditional customs'. This has resulted in several indigenous communities in Mexico maintaining local systems, notably those of Cherán, and areas under Councils of Good Government control.