Tom Tancredo writes in Breitbart,
Because of the relative ease of crossing the border and Mexico’s liberal definition of Mexican citizenship, we have the situation recently described by author Ann Coulter, who discovered that persons of Mexican origin now residing in the United States — legal and illegal– are equal in number to over 25 percent of the 130 million population of Mexico.
Let me put this in stark economic terms: Mexico’s national income grows in direct proportion to the size of the illegal Mexican population inside the United States. Does that help explain the Mexican fixation on U.S. politics? Mexico’s most profitable export to the U.S. is not oil or avocados or automobile parts, it is people.
…Mexicans living and working in the U.S. send home over $20 billion annually in cash remittances — more than Mexico earns in foreign currency from tourism or any export commodity.
In 1979, Mexico received only $177,000 (U.S. Dollars) in remittances; in 2016 it was $26.1 BILLION — over 90 percent of it from persons living in the United States.
Read more here.