I'm shocked to see Trump winning some precincts in South Texas. Considering that's mostly Mexican territory.
They might be mexican americans but theres a lot of people whose roots might be in Mexico but family history has been in the area for a long time and apparently dislike illegal immigration. One lesson of 2016 is to not assume that voting patterns are static.
It's very encouraging to see a Democrat realize this. If the other members of your party acknowledged such things rather than assuming votes simply because of someone's race, the world would be much better place.