They do the jobs that even blacks won't do
Here's a recent quote from Vicente Fox:
"There is no doubt that Mexicans, filled with dignity, willingness and ability to work are doing jobs that not even blacks want to do there in the United States..."
I believe at this point in time my "liberal" readers might want to read up on Mexico's racial hierarchy. Try "America's Imported Caste System" as a starting point.
UPDATE: If you have access to a site snake program, you might want to cache everything in this search for "the jobs americans won t do". I can almost hear history being rewrit as the White House and others work to cleanse their various statements of that phrase.