The defeat of the PRI (Institutional Revolutionary Party) by the PAN (National Action Party) in 2000 was an important historical event in Mexican politics. It was the first time there was a smooth transition of power without there being a coup, or revolution, but the significance of the 2000 election was the temporary fall of a political party that had ruled the country and entrenched itself in the state's affairs for seven decades, starting its dominance since its inception in 1929.

For many political analysts, this is still a topic of discussion; but, to fully understand the development of the party, we must discuss some history. Mexico never intended to become a one-party dominated state. President Plutarco Elías Calles, himself, encouraged political competition within the state. There are many reasons why the government encouraged political opposition; one of them being, Mexico needed to gain recognition from the United States, the Mexican government had to keep democratic forms of government although the exercise of power was not democratic. The PRI was allowed to entrench itself into Mexican society through the many revolutions that took place after the main Mexican revolution. The small revolts through the several pockets of the country ultimately led to the placement of Porfirio Diaz , Mexico's dictator for 30 years. His regime was called the Porfiriatowhich was a time that saw the expansion of the country's infrastructure and allowed the party to become extremely attached to the economic modernization of Mexico. During the presidency of Lázaro Cárdenas, the PRI became the party of the people, infilitrating the mobilized structures of the social groups that organized the government before and after the revolution, being able to secure a spot in maintaining stability.

The PRI's regime secured Mexico from all the civil wars other Latin American countries had throughout the 1960s-1980s. The dominance it held politically, economically, and socially allowed the state to act virtually act as a one-party state where every aspect of daily life revolved around the party.

The reduction of political turmoil and the control the PRI had over the economy actually helped Mexico prosper economically. During the 1940's to the 1970's , there was an economic phenomenon which economists call the Mexican miracle that produced steady economic growth of 3 to 4 percent and 3 percent inflation yearly. Government's investment in education led to more growth in the country, allowing Mexicans to move out of the country and into the city. This time also saw the creation of two prestigious Mexican universities, Instituto Politécnico Nacional or IPN and the Monterrey Institute of Technology and Higher Education, known in Mexico as the Tec de Monterrey.

Unfortunately, during the 1980's the PRI began to lose dominance in the legislative branch. Before the 1980's, the PRI-controlled more than 70 percent of the seats in the legislative. Due to electoral reforms, Mexico adopted a mix electoral system which allowed half of the Chamber of Deputies to be elected by Proportional Representation, which a method where the percentage of votes equals the percentage of seats a political party receives in the house or chamber and the half by Single Member District Plurality, a system where one district elects one leader to the legislature.

Overall, these electoral reforms allowed other political parties to gain more control of seats in congress allowing more political competition to develop. Which overall developed to President Vicente Fox winning the presidential election in 2000 for the PAN.

In spite of, the PRI being known for their corrupt actions in government. The party, for many, allowed the country to grow economically and keep a stable image. The dominant party system in Mexico actually helped the nation transition from an agrarian society to more of an industrialized society.