IMO that cannot be emphasized enough: the national strategy of the foreign government. Mexican groups in the United States report to the corrput Mexican government's Instituteof Mexicans Living Abroad, the office that replaced Fox's migrant affairs office. As long as we blame the ILLEGAL immigrant that foreign government and "our" government can portray the ILLEGAL immigrant as a victim of American "racism" and "xenophobia."
This is about Mexico's corrupt government's policy of the Mexican Diaspora, "Mexico, a nation without borders." Note: Mexico finds that the longer its expatriates stay away from Mexico and in the U.S., the more they come to love Mexico. Mexico's corrupt government and both of our political parties support it.
Who can know the effect of "the insidious costs of the illegal hiring practices of contractors, farmers and factory owners -- costs for medical care for uninsured illegals, increased law enforcement, growing entitlements and the need for dual documentation in business and government?" Throw in education and the answer is, California!