"Mexican immigrants living in the United States. On the eve of President Obama’s visit to Mexico, this profile reveals that a record 12.7 million Mexican immigrants lived in the U.S. in 2008, a 17-fold increase since 1970.
Mexicans now account for 32% of all U.S. immigrants and more than one-in-ten of all persons born in Mexico now reside in the U.S.
http://pewhispanic.org/factsheets/factsheet.php?FactsheetID=47
No other country in the world has as many total immigrants from all countries as the United States has immigrants from Mexico alone.
More than half (55%) of Mexican immigrants in the U.S. are unauthorized.
Immigrants from Mexico are younger than other immigrants and less likely to be U.S. citizens. Compared with the U.S. born population, Mexican immigrants are more likely to be male, married, and live in larger households. They are less educated, more likely to be unemployed, have lower incomes and higher poverty rates.
The statistical profile is based on data from the March 2008 Current Population Survey.
The profile, Mexican Immigrants in the United States, 2008."