sentences:  The policies promoting industrial growth helped fuel the growth of Mexico's north as a center of economic dynamism, with the city of Monterrey becoming Mexico's second largest.The general economic prosperity served to legitimize PRI hegemony in the eyes of most Mexicans, and for decades the party faced no real opposition on any level of government.On the rare occasions when an opposition candidate, usually from the conservative National Action Party, whose strength was in Mexico's north, garnered a majority of votes in an election.