Who's the racist now?
This was a "gaffe", a politician accidentaly telling a bit of the truth in public. Always a great embarassment to the perpetrator to be sure, but also quite amusing.
Another way of saying the same thing is that the Mexican government and business community have done such a crappy job of growing the Mexican economy that Mexico's desperate citizens are fleeing north, willing to accept even the most menial jobs on offer, at bottom-of-the-barrel wages that are so low that otherwise unemployable Americans know they can do better on welfare than to take such jobs (and that a disproportionate number of such 'minimally employable' Americans are blacks).
Once they get here, of course, they frequently find that they can do even better than that, if they are willing to work hard, long, and for less.