The 40% of Blacks polled feeling strong anti-immigration sentiment surprised me again. Why? was this racially motivated? was it broad acceptance of anti-Mexican worker sentiment or something else?
They should - they are overwhelmingly most likely to lose out because of illegal immigration. The rich benefit from it, the poor suffer.
People often confuse group identity and views on immigration with racism. Someone may even say "I hate those Mexicans, they come here and take our jobs ...". Are they racist? Probably not - what they hate is the net effect of the uncontrolled immigration. If it happened that it was masses of Chinese people or White people illegally coming across the border and taking their jobs, their issue would be with them instead.
i.e. it's not the color of the people, even though that may be the superficial reason stated - that's just the obvious group label to use and it's the unfair situation and impact that people object to.