The Institutional Revolutionary Party (PRI) is a political party in Mexico, founded in 1929. It played a dominant role in Mexican politics for much of the 20th century, promoting policies of economic nationalism and social reform. The PRI was known for its centralized control and was often criticized for authoritarian practices during its long period in power. In the late 20th century, the PRI began to face increasing competition and criticism, leading to significant political reforms. The party lost the presidency in 2000, marking the end of its uninterrupted rule. Since then, the PRI has struggled to regain its former influence in Mexican politics, facing challenges from parties like the National Action Party (PAN) and the Party of the Democratic Revolution (PRD).