The Senate of the Republic, (Spanish: Senado de la República) constitutionally Chamber of Senators of the Honorable Congress of the Union (Spanish: Cámara de Senadores del H. Congreso de la Unión), is the upper house of Mexico's bicameral Congress.

After a series of reforms during the 1990s, it is now made up of 128 senators:[1]

  • Two for each of the 32 states elected under the principle of relative majority;
  • One for each of the 32 states and one for the Federal District, assigned under the principle of first minority (i.e. awarded to the party who had won the second highest number of votes within the state or Federal District);
  • Thirty-two national senators-at-large, divided among the parties in proportion to their share of the national vote.

In a senatorial race, each party nominates two candidates who run and are elected together by direct vote. The party of the two candidates that won the second highest vote within the state or the Federal District then assigns a senator to occupy the third seat (first minority seat), according to the list of candidates that the party registered with the Federal Electoral Institute (IFE).

Senators serve six-year terms, running concurrently with the President of Mexico. Special elections are rare, as substitutes are chosen at every election.

The Senate is completely renewed every six years, since senators are barred from immediate reelection. This will change at the 2018 election.

Term and current composition

In Spanish, it is conventional to refer to each Legislature of the Senate by the Roman numeral of its term.

The current session (whose term lasts from 2015 to 2018) is known as the LXIII Legislatura (63rd Legislature).

Senators are elected to serve during two legislatures of the Mexican Chamber of Deputies. Thus, current Senators (who were elected in the general election of July 1, 2012) will serve during the 62nd and 63rd Legislatures of the Chamber of Deputies.

The current composition of the Senate is as follows:

Party First
At-large Total
PRI 33 11 11 55
PAN 16 11 7 34
PT 6 6 7 19
PRD 3 1 3 7
PVEM 4 0 2 6
No Party 2 3 2 7

Election of Senators

Eligibility requirements

According to the Constitution, senators are the representatives of the nation. To be a senator, for any of the two principles of choice, you must meet the following requirements:[2]

  • Being a Mexican citizen by birth, in the exercise of their rights.
  • Be twenty-five years old on election day
  • Being from the state in the election, or neighbor of him with effective residence of more than six months prior to the date of the election, or in the case of candidates is made by proportional representation of any of the states that as the constituency, with the same details.
  • Not being active duty in the military or have control of police or rural gendarmerie at least ninety days before the election.
  • Not to be secretary or undersecretary of state unless it is definitively separated from office at least ninety days before the election.
  • Not be Minister of the Supreme Court unless definitively separated from office three years before the election.
  • No minister of some religious cult.

Election process

Senators are elected for a period of six years, corresponding to two legislatures and can not be reelected for the immediate period, although alternately.

They are elected by direct popular suffrage and secret ballot in every state of the republic. Each political party registers a list with two formulas of candidates, consisting of two owners and their alternates: the number 1 of the formula First Formula is denominated to him, and 2, Second Formula. The formula of candidates obtaining the highest number of votes is elected complete, becoming the first two senators of the entity; the third senate is awarded to the candidate of First Formula of the political party that won second place of votes or first minority.

They are also 32 senators elected by proportional representation. For this election each political party registers a list of 32 candidates, and these are allocated by proportional representation according to the number of votes obtained by each political party in the national election. Senado2.jpg

Governing bodies

For their internal government has two main instances, namely:

  • Board: Composed of a Chairman, three Vice - Chairpersons and four Secretaries, elected for each regular session of the House, the President is the turn of the Senate and is the head and representative of the Chamber.
  • Political Coordination Board: Considered the true governing body of the Chamber consists of a chairman and six members, which always include the Coordinators of the different parliamentary factions of political parties represented in the Senate.[3]


For the office of legislative affairs Senators integrate in Commissions that are dedicated to a particular issue. The most important committees are those of: Interior, Constitutional Issues, Defense, Finance, Justice, among others. Each Senator belongs to at least three different commissions, and each committee shall elect a Chairman and two Secretaries 5 (according to the Commission) to coordinate their work.


A senator holds office for a period of six years for which he was elected (from September 1 of the year of its election to the 31 August six years later), divided into two legislatures of three years each.

From 1 September 2015 is installed LXIII Legislature, which will end its term on 31 August 2018. Senators were elected to office in the 2012 elections for a period of six years and are at their posts from 1 September of that year, therefore they will hold office from the LXII Legislature to LXIII Legislature.


The two chambers of the General Congress divided its exercise in two ordinary sessions, the first from September 1 to December 15 and the second from February 1 to April 30, it should be required may convene special sessions to dispatch urgent or pertinent matters.

The time between the regular sessions known as Recesses. There are two recesses that run from December 16 to January 31 and May 1 to August 31. During breaks, the Permanent Commission of the Congress is installed and serves as depository of the legislature; It is composed of 37 members, of which 19 Deputies and 18 Senators are appointed by their respective chambers the day before the closing of the regular sessions.

The sessions of the Standing Committee are held in the Senate during the first recess and the House of Representatives in the second recess.


Among the most important functions of the Senate it is to ratify or reject the president's proposals regarding:[4]

  • Ministers of the Supreme Court of Justice of the Nation
  • Attorney General of the Republic
  • Heads of Autonomous Bodies
  • Diplomatic Representatives (Ambassadors and Consuls)
  • International deals



External links

Coordinates: 19°26′11.57″N 99°8′19.37″W / 19.4365472°N 99.1387139°W / 19.4365472; -99.1387139