Congress has maintained significant interest in neighboring Mexico, a close ally and top trade partner whose political and economic situation has significant ramifications for the United States. President Enrique Pena Nieto of the centrist Institutional Revolutionary Party (PRI) assumed the Mexican presidency on December 1, 2012, after 12 years of rule by the conservative National Action Party (PAN). Pena Nieto has enacted structural reforms and bolstered economic relations with the United States, but observers maintain he mishandled recent high-profile human rights cases and allegations of a conflict of interest between his family and a government contractor."