During the PRI's 12-year hiatus from presidency, its members firmly opposed such measures proposed by then-ruling National Action Party, arguing the country would lose sovereignty by allowing foreign investment in Pemex.

NPR: Mexico's Ruling Party Says 'Yes' To Energy Reform

The conservative Grand National Party draws much of its support from the country's older voters.

ECONOMIST: The generational divide weighs on politics

Not just in politics--the country's dominant political party, the National Congress Party, is, after all, headed by Sonia Gandhi, a woman who made our ranking of the World's Most Powerful Women--but in big business, too.

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