National news tends to locate things in Texas to the county, for some reason. Particularly with elections, since they're administered by county governments. So, here's a Texas counties primer, in case you need it tomorrow:
Harris county (pop 5.1 mil) - home of Houston
Tarrant county (pop 2.6 mil) - home of Fort Worth
Dallas county (pop - 2.6 mil) - home of Dallas
Bexar county (pop 2.2 mil) - home of San Antonio
Travis county (pop 1.4 mil) - home of Austin
And to save you some math, that comes out to 13.9 million, of the 30.5 million in the whole state. So if something fucky is happening in these places, that represents 45% of the entire population of Texas.
Just fyi
@jenniferplusplus iirc, Texas also has one of the counties with the *smallest* population in the US, to counterbalance the ones you named.