The politics of Mexico function within the framework of the federal presidential representative democratic republic whose government is based on a multi-party congressional system, where the President of Mexico is both head of state and head of government. The federal government represents the United Mexican States. It is divided into three branches: executive, legislative, and judicial, established by the Political Constitution of the United Mexican States, published in 1917. The constituent states of the federation must also have a republican government based on a congressional system established by their respective constitutions.
Executive power is exercised by the executive branch, headed by the President, who is advised by a cabinet of secretaries independent of the legislature. Legislative power is vested in the Congress of the Union, a two-chamber legislature comprising the Senate of the Republic and the Chamber of Deputies. Judicial power is exercised by the judiciary, consisting of the Supreme Court of Justice of the Nation, the Council of the Federal Judiciary, and the collegiate, unitary, and district tribunals.
Framework of twentieth-century politics The Mexican Revolution (1910–1920) followed the overturn of Porfirio Díaz's dictatorship and ended with a new Mexican government being established within the legal framework of the Constitution of 1917.Duncan, Raymond. "The Mexican Constitution OF 1917 compared with the Constitution of 1857" in American Academy of Political and Social Science. Philadelphia: 1917, p. 8–122. The following regime can be considered a semi-authoritarian political model (or hybrid regime).Ai Camp, Roderic. "Democratizing Mexican Politics, 1982–2012" in Oxford Research Encyclopedia. Claremont: 2015, p. 1. In 1920, a successful general in the Revolution named Alvaro Obregón overthrew the temporary government of the revolutionary leader Venustiano Carranza, which resulted in his election as the President of Mexico. He was then replaced by Plutarco Elías Calles, who ruled Mexico from 1924 to 1928. After a rule change that prevented two mandates by the same person, Obregón returned to power in 1928 but was assassinated shortly after. As a result, outgoing president Calles founded a political party, the Partido Nacional Revolucionario (PNR), to solve the immediate political crisis of the assassination and to create a long-term framework for political stability, especially the transition of presidential regimes. The period from 1920–1934 in Mexico was marked by a strong presence of military in government and a failure to implement revolutionary reforms.Raby, David. "Mexican Political and Social Development since 1920" in Canadian Association of Latin American and Caribbean Studies. Toronto: 1976, p. 27.
Under President Lázaro Cárdenas (1934–40), the party transformed into the Partido de la Revolución Mexicana, which was organized on a corporate basis, with peasants, labor, the popular sector, and the military each having a division, with power centralized. The PRM aimed to mediate conflicts between competing sectors within the party, becoming an extension of the Mexican state. In 1946, the party was transformed into the Institutional Revolutionary Party (PRI), and the army was no longer a sector.Schmidt, Samuel. "Politics and Government: 1946–1996" in Encyclopedia of Mexico. Chicago: Fitzroy Dearborn 1997, pp. 1121–27.Brachet-Márquez, Viviane. "Politics and Government: 1910–1946" in Encyclopedia of Mexico. Chicago: Fitzroy Dearborn 1997, pp. 1118–21. During this time, the government nationalized key industries, such as oil, and implemented land reforms that redistributed property to peasants.Rippy, Merrill. "The Nationalized Oil Industry of Mexico: 1938–55". Chicago: The Southwestern Social Science Quarterly 1957, pp. 6–18.Dell, Melissa. "Path dependence in development: Evidence from the Mexican Revolution". Boston: Harvard University Press 2012, pp. 1–37.
Mexico experienced political tension and rising economic instability throughout the second decade of the twentieth century. The late 1960s and early 1970s saw multiple protests from students and left-wing groups against PRI's authoritarian rule, to which the government responded with a crackdown that culminated in the infamous Tlatelolco Massacre of 1968, in which hundreds of protesters were killed. However, the year 1982 gave way to market restructuring policies and gradual political reforms that prompted the democratic transition of Mexico (1982–2012).Ai Camp, Roderic. Democratizing Mexican Politics, 1982–2012. Oxford University Press: 2015 The first efforts to introduce free and fair elections came with President Miguel de la Madrid in 1983. Still, the attempt was unsuccessful, as he was opposed by politicians in his party.
The 1988 elections, won by Carlos Salinas de Gortari against Cuauhtémoc Cárdenas (son of former President Lázaro Cárdenas), were regarded as "the most fraudulent in Mexico's history.”Schmidt, "Politics and Government, 1946–1996", p. 1126. In 1989, politicians of the PRI who rejected Salinas's pro-market reforms formed the Party of the Democratic Revolution.Bruhn, Kathleen. Taking on Goliath: The Emergence of a New Left Party and the Struggle for Democracy in Mexico. Penn State University Press 2004 In the wake of the fraudulent 1988 elections, the administration of elections was taken out of the hands of the Mexican government's Ministry of the Interior (Gobernación), and the Instituto Federal Electoral (IFE) was created in 1990 to ensure free and fair elections and build public confidence in the process.Uges, Antonio, "Citizens' Views on Electoral Governance in Mexico accessed 6 March 2020
Political parties
Constitutionally, political parties in Mexico must promote the participation of the people in the democratic life of the country, contribute to the representation of the nation and citizens, and be the access through which citizens can participate in public office, through whatever programs, principles, and ideals they postulate. All political parties must be registered with the National Electoral Institute (, INE), the institution in charge of organizing and overseeing the federal electoral processes, and must obtain at least 3% of votes in the federal elections to keep their registry. Registered political parties receive public funding for their operation and can also get private funding within the limits prescribed by the law. As of , the following political parties are registered with the INE, and all have representatives in the Congress of the Union: The National Action Party (, PAN), founded in 1939; The Institutional Revolutionary Party (, PRI), founded in 1929; The Green Ecological Party (, PVEM), founded in 1986 but lost its registration for two consecutive elections; it has retained its registration since 1993; The Labor Party (, PT), founded in 1990; Citizens’ Movement (, MC), founded in 1999; The National Regeneration Movement (), founded in 2014;
Political parties can form alliances or coalitions to nominate candidates for any particular election. The coalition must identify itself with a specific name and logo. Proportional representation (plurinominal) seats are assigned to it based on the percentage of votes obtained in the elections. Then, it reassigns them to the constituent political parties. Once each party in the coalition has been assigned plurinominal seats, they do not necessarily continue to work as a coalition in government.
Throughout the 20th century, the PRI had an almost hegemonic power at the state and federal levels, which slowly began to recede in the late 1980s. Even though since the 1940s, the PAN had won a couple of seats in Congress and its first presidential municipality (in ) in 1947, it wasn't until 1989 that the first non-PRI state governor was elected (in ). It was in 1997 that the PRI lost its absolute majority in the Congress of the Union. In 2000, the first non-PRI President since 1929 was elected in what was regarded as the cleanest Mexican election since the end of the Mexican Revolution in 1920.Duncan, Raymond. "Mexico's Democratic Transition: The Search for New Reform Coalitions" in Law and Business Reviews of the Americas. Mexico: 2003, p. 283.
Major political parties
Since , four political parties have dominated the politics of Mexico: the Institutional Revolutionary Party (PRI), the National Action Party (PAN), the Party of the Democratic Revolution (PRD), and the National Regeneration Movement (Morena).
Founded in 1929 as the Partido Nacional Revolucionario ("National Revolutionary Party"), the PRI dominated Mexican politics for over 70 years, bringing to power 11 different governments.
The PAN, founded in 1939, did not win its first governorship until 1989; its candidates won the presidency in 2000 and 2006.
The PRD's beginnings date back to 1988 when dissident members of the PRI decided to challenge the leadership and nominated Cuauhtémoc Cárdenas for President of Mexico. Cárdenas lost in a highly contested election, but a new political party was born, and the party emerged as a third force in Mexican politics, even though it never captured the presidency.
Morena grew out of a dispute between Andrés Manuel López Obrador and other PRD leaders after losing in the 2012 presidential election. Morena won official recognition in 2014 and dominated the 2018 and 2024 elections.
According to a 2017 survey by the National Autonomous University of Mexico, 74 percent of Mexicans believe that Mexico's electoral system is not transparent and distrust official results. However, Freedom House shows that popular belief in free and fair elections has increased ever since. The main political issues in Mexico were crime, corruption and economy according to a 2026 Enkoll poll.
Elections and political composition of the institutions
Suffrage is universal, free, secret, and direct for all Mexican citizens 18 and older and is compulsory (but not enforced). The identity document in Mexico also serves as the voting card, so all citizens are automatically registered for all elections; that is, no pre-registration is necessary for every election. All elections are direct; that is, no electoral college is constituted for any of the federal, state, or municipal elections. Only when an incumbent president is absent (either through resignation, impeachment, or death) does the Congress of the Union itself act as an electoral college to elect an interim president by absolute majority.