The bracero program was formulated by the US government to import cheap Mexican labor back in the 1940s.
It came on the heels of the great Mexican American repatriation during the Great Depression where legal US citizens of Mexican/Latino descent were forcibly repatriated to Mexico, DESPITE THE FACT THAT THEY WERE LEGAL US CITIZENS.
The braceros were legal insofar as US law and bilateral agreements between Mexico and the US allowed for Mexican nationals to come to the US to work.
But these were not US citizens.
Plus, many Mexican Americans who can trace their lineage to Mexico (especially in the Southwestern US and Texas) have family histories that place them in parts of this country that were once part of Mexico or under Spanish control.
That doesn't mean they have any special claims, but it cannot be argued that these people aren't US citizens who should forego due process for the sake of political expediency or whatever right wing persecution "flavor of the week" the media parrots to the American public.
Still, the flaw in the anti-Mexican backlash is that it spreads the blame to anyone who is brown or who has a Spanish surname: they become the forbidden Other - the untermenschen class that is suspect regardless of their citizenship or immigration status because they "look Mexican."
I am one of those people: I am a US citizen who has never had to prove his national origin to a law enforcement officer in the United States because of the color of my skin or my Spanish surname.
But reactionary legislation in some states would have me prove that now. And the street-level application of those laws, regardless of whatever statutory safeguards are set, mean that a blond-haired, blue eyed person would not be held to the same scrutiny I could conceivably be held to. It places all people who fall in the forbidden Other category into a suspect class.
You cannot trust the motivations of racists who disguise their intentions behind authoritarian appeals to the "rule of law" or people who cannot differentiate between what is just, humane, or fundamentally fair.
http://dnn.epcc.edu/nwlibrary/borderlands/24/mex%20repat.htm