I'm shocked to see Trump winning some precincts in South Texas. Considering that's mostly Mexican territory.
It's actually not necessarily that surprising, considering that historically many of the wealthy Tejano ranchers and landowners are fully complicit in the exploitation of workers in the ranching and farms of South Texas from the beginning of the Republic.
https://thenewinquiry.com/the-chaparral-insurgents-of-south-texas/http://www.bizjournals.com/sanantonio/stories/2002/09/09/daily8.htmlhttps://tshaonline.org/handbook/online/articles/wmtknThere are likely better links/articles to discuss the complexity of the Tejano population in South Texas, and although I haven't run the data on the individual precincts that voted for Trump, it is not surprising to see Tejano landowners continuing to back a reactionary and feudalistic social structure, just the same as an Anglo family farm in the Central Valley of California running similar size acreage...
Cesar Chavez actively worked to unionize both, regardless of the historical ancestry of the oppressors.