There's also a very big difference between having "anti-Mexican sentiment", for example being against any further legal immigration for the foreseeable future,

There's also a very big difference between having "anti-Mexican sentiment", for example being against any further legal immigration for the foreseeable future, and having sentiment against Jose and his family who run your favorite Mexican restaurant. People who, if you're smart, you get to know, and with enough people doing that, help the "melting pot" metaphor do its magic. Getting back to Chinese restaurants, for a long while I lived in a small apartment on the same block as the Cambridge, MA Necco factory. Not all that long after moving in, a Chinese restaurant opened up in the building between our apartment and the major thoroughfare. We made a point of getting the owner's phone number so we could call him if we noticed anything happening to the restaurant.