Besides some relative stability in social terms, it really depended on individual presidents, as such party doesn't really have a political, economic or social platform on its own.
For instance, presidents Manuel Avila Camacho (1940-1946) and Miguel Aleman (1946-1952) provided the groundwork for the Mexican Miracle (1940s-1970s), a period of rapid industrialization and high economic growth; on the other hand, presidents Luis Echeverria (1970-1976) and Jose Lopez Portillo (1976-1982) are known for causing the Lost Decade (1980's), a period of hyperinflation, devaluation and a collapsing economy.
PRI
Yes. From 1929 until the 2000 presidential elections, PRI was the leading party in Mexico.
PRI
It is the other way around. The majority of the unions in Mexico are affiliated, and controled, by the PRI. This has changed slightly over the last 10 yrs or so since PRI lost power, though Mexican "sindicatos patronales" are PRI owned.
PRI
The Partido Accion Nacional or PAN.
Partido Revolucionario Institucional (PRI)
Ernesto Zedillo (term: 1994-2000) qualifies as such.
The Spanish Empire controlled Mexico for over three centuries.
The Partido Revolucionario Institucional, or PRI.
Spain controlled Mexico, which began the struggle for independence on September 16, 1810 and consolidated it on September 27, 1821.
The Institutional Revolutionary Party (PRI), whose members held the presidential seat for more than 70 years in Mexico.