San Antonio has lots of retired military and they tend to be conservative. San Antonio is too humid and hot for me in the Summer. I like the arid dry part of Texas, but I grew up there. And I spent 14 years in NM, hot & dry (and in the mountains).
There are only a few counties in Texas that are liberal tainted. Austin is one of those areas.
My daughter and son-in-law live in Williamson County, just outside Austin. Very conservative area.
General rule, Cities are Liberal, Rural Areas are Conservative.
The Mexican border influence is a consideration now. It is not a racial issue, but corruption issue. Proximity to the border increases potential problems with violence.
It is not humid here in San Antonio - hot though - yes, plenty of that! Now Houston - that there’s humid!!!! It just never seems to rain here. La Nina is killing us. Drought is unreal. As to politics, generally Bexar County goes GOP, but this last time actually went Obama.