url no longer exists: http://www.indiana.edu/~jah/mexico/rfigueroa.html
Here one will find that "recent constitutional reforms . . . provide that Mexican nationality is not lost as a result of obtaining a second nationality . . . When two countries share large groups of population, both governments share the responsibility for them." [end]
http://www.pbs.org/pov/pov2003/thesixthsection/special_mexican.html
One of the most effective means that Mexico maintains the loyalty of its citizens beyond borders (and attempts to attract Americans of Mexican heritage) is the home town association network in the U.S. [end]
"To date, the population of Mexican descent living in the United States represents 20% of the population of Mexico; it is estimated that, by the year 2050, this percentage will have grown to 39% . . . The Program for Mexican Communities Abroad has been carrying out, for seven years now, activities to promote greater closeness with our countrymen who reside abroad . . . ."
I believe the National Council for Mexican Communities Abroad coordinates the various Mexican government agencies and their agents residing in the U.S. The purpose is to teach and build loyalty to Mexican language, history, culture; and, to benefit Mexico as much as possible. [End] With the U.S. citizens paying for most of it.
As Heather MacDonald said, "Mexican leaders have . . . tasked their nation’s U.S. consulates with spreading Mexican culture into American schools and communities. . . Since 1990, Mexico has embarked on a series of initiatives to import Mexican culture into the U.S. Mexico’s five-year development plan in 1995 announced that the 'Mexican nation extends beyond . . . its border' -- into the United States. Accordingly, the government would 'strengthen solidarity programs with the Mexican communities abroad by emphasizing their Mexican roots, and supporting literacy programs in Spanish and the teaching of the history, values, and traditions of our country.'" Again with the U.S. citizens paying for it.
I believe that it is still true official policy of the Mexican government: "Mexican nationality is not lost as a result of obtaining a second nationality."
Or put another way, the emigrant must take his stomach with him but s/he is required to leave his heart in Mexico.
re: the url's that were missing. Anyone could select a string of characters and use google to find a copy somewhere.
I googled for this string of characters from my post above.
"When two countries share large groups of population, both governments share the responsibility for them"
google returned this among a few others (including FR, my old reply and the reply above made minutes ago). google ain't all bad.
A Nation beyond Its Borders: The Program for Mexican Communities Abroad
This is an old document but I think it still holds true.