You are correct that groups in the United States have had an enormous impact on Mexican politics. In 2003, Choicepoint was busted buying the secret Mexican voter files for the George W. Bush administration.

http://www.theguardian.com/world/2003/may/05/colombia.usa

While Mexico does not have the resource curse, they are close by, in our time zones, and can provide massive labor exploitation if policies are tuned to make Mexicans desperate.