July 1, 2012 Held


United Mexican States

Election for Camara de Senadores (Mexican Senate)


Voter Participation

Cast Votes:50,310,328
Valid Votes:47,412,660
Invalid Votes:2,897,668

Vote Share by Party:

Party Seats Won Seats Change Votes

Institutional Revolutionary Party 58 - 15,679,729


National Action Party 44 - 13,245,088


Party of the Democratic Revolution 19 - 9,353,879


Green Ecological Party of Mexico (Partido Verde Ecologista de México) 3 - 2,881,026


Labor Party (Partido del Trabajo) 2 - 2,339,923


New Alliance Party (Partido Nueva Alianza) 1 - - 1,855,403


Convergence 1 - 2,025,045

Election Results Modified: May 10, 2024

General Information

At stake in this election:

  • 128 seats in the Senate (Camara de Senadores)

Description of government structure:

  • Chief of State: President Felipe CALDERON
  • Head of Government: President Felipe CALDERON
  • Assembly: Mexico has a bicameral National Congress (Congreso de la Union) consisting of the Senate (Camara de Senadores) with 128 seats and the Chamber of Deputies (Camara de Diputados) with 500 seats.

Description of electoral system:

  • The President is elected by plurality vote to serve a 6-year term.
  • In the Senate (Camara de Senadores), 96 members are elected by plurality vote in multi-member constituencies to serve 6-year terms and 32 members are elected through a closed-list proportional representation system to serve 6-year terms*. In the Chamber of Deputies (Camara de Diputados), 300 members are elected by plurality vote in single-member constituencies to serve 3-year terms and 200 members are elected through a closed-list proportional representation system to serve 3-year terms.**

* The voter votes at the state level. 96 Senators are elected from closed party lists in 32 districts of three seats, each corresponding to a state. The top vote-getting list wins two seats. The next-placed list wins one. Parties may nominate two candidates in any given district. 32 more Senators are elected from closed, nation-wide party lists. National vote shares are determined by summing state-level results. The threshold in this tier is two percent.

** The voter casts one vote at the single-member district level. PR seats are allocated from closed lists in five multi-member districts of 40 seats each in order to make each party's seat share proportional to its vote share at the MMD level. No party may seat more than 300 deputies. No party's seat share may be more than eight percent in excess of its vote share. This rule does not hold, however, if the disproportion results in the single-member district tier. A party may not contest seats in the proportional tier unless it registers candidates in at least 200 single-member constituencies. The threshold in the proportional tier is two percent.

Main parties in the electoral race:

Population and number of registered voters:

  • Population: 122,070,963 (2012)
  • Registered Voters: 77,547,511 (July 2012 Figure represents registration to vote in Chamber of Deputies elections. Reported registration rate for Senate elections was 77,651,019. Source: IFE.)

Gender Data:

·         Female Population: 61,356,422 (2012)

·         Is Mexico a signatory to CEDAW: Yes (17 July 1980)

·         Has Mexico ratified CEDAW: Yes (23 March 1981)

·         Gender Quota: Yes 

·         Female candidates in this election: No

·         Number of Female Parliamentarians: 184 (Chamber of Deputies); 42 (Senate) (following the 2012 elections)

·         Human Development Index Position: 74 (2014)

·         Social Institutions and Gender Index (SIGI) Categorization: N/A

Disability Data:

·         Is Mexico a signatory to CRPD: Yes (30 March 2007)

·         Has Mexico ratified CRPD: Yes (17 December 2007)

·         Population with a disability: 18,310,644 (est.)

Election Modified: May 10, 2024

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