Dallas county is blue, their US rep, mayor and city council are almost always democrat. IIRC so is Travis county(Austin). I don’t know if Harris county and bexar (Houston and SA) are always blue, but they are probably trending that way. City of Houston definitely liberal, but Harris county is a much bigger county than Dallas and has a lot of suburban cities in it whereas Dallas county is almost all city of Dallas. IIRC all of the heavily populated counties were blue in the last presidential election to include Tarrant County (Fort Worth/Arlington). My former home county, Tarrant, is almost always leaning red so that was surprising to me to see the map turn blue. The Texas major cities have changed a lot over the last 20 years. Austin is about to break 1 mil if it hasn’t already and Fort Worth isn’t far behind. So yes the liberals are in the cities. And in DFW the handful of heavily populated suburban counties are red.