Sexenio is the popular term for the term of office on the President of Mexico. Under Article 83 of the Mexican Constitution, the president is limited to a single six-year term, and no one who holds the office even on a caretaker basis is permitted to run for or hold the office again. It is one of the country's most important political institutions, because it is one of the few significant limitations on executive power in Mexico, which is strong at local, state, and national levels. The sexenio is a reaction to the failed experiment of re-election in Mexico during part of the Porfiriato era (1876–1911).
In addition to restricting the presidency, state governors also face this restriction; no one elected as a governor may ever hold the post again, even on an interim basis.
After dictator Antonio López de Santa Anna was deposed in the Revolution of Ayutla, a series of laws known as La Reforma were introduced, including a new 1857 Constitution (based on the earlier 1824 constitution) which limited the president to a single four-year term. General Porfirio Díaz seized power in the Plan of Tuxtepec, got the ban on reelection repealed, and ended up winning eight elections, between 1877 and 1904, before he was deposed in 1911. This period, called the Porfiriato (1876–1911), soured public interest in reelection, and the ban was reintroduced not long after.[1]
When the Mexican Constitution of 1917 was introduced, the president was limited to a single four-year term. During the presidency of Plutarco Elías Calles, the term of office was extended to six years, beginning with the 1928-1934 term. Former president Álvaro Obregón launched a successful campaign to alter the Constitution to only ban consecutive terms. He ran in the 1928 election and won, but was assassinated before he could take office again, and an out-of-cycle 1929 election was held to pick someone to serve the remainder of the term. The total ban on presidential reelection was reinstated in 1932, alongside a new ban on reelection in Congress the year after that. Campaigns to end the reelection ban were launched in 1964 and 1991, both times unsuccessfully.[1]
Although the intention of the sexenio was to prevent presidential dictatorship, this system has not met with total success. This was in part because the presidency was monopolized by the Institutional Revolutionary Party (PRI) from 1929 to 2000. From 1929 to 1994, presidents approaching the end of their sexenio personally chose the PRI's presidential nominee in the next election. The PRI's dominance was so absolute that the president essentially chose his successor; in the case of Plutarco Elías Calles, there is strong evidence suggesting that he basically continued ruling through the next three presidents by using them as puppets, leading to the six-year period to being called the Maximato, after Calles's sobriquet jefe máximo ("Maximum Leader"). The PRI's grip on power was eventually broken at the 2000 election, where Vicente Fox (PAN) became the first opposition candidate elected president in three generations.
The ban on reelection is so entrenched in Mexican politics that, even when Article 59 of the Constitution was amended to allow legislators to run for multiple consecutive terms, the ban on any sort of presidential reelection remained in place. It is also referenced in street names in Mexican cities, such as Puerto Peñasco's "Calle No Reelección" ("No Re-election Street"), a name also present in several other cities.