BlastProcessing
Member
Completely talking out of my ass here, but if I had to guess?
It's more towards the northwestern areas of Texas which are pretty empty. You can count on Houston, Austin, Dallas / Ft. Worth going blue. Counties on the Rio Grand including Lardeo went blue in a big way in 2008 and 2012. Places like El Paso and Odessa / Midland went blue both years too. But the north western section is deep red territory. I would guess that if you want to try to flip a large metropolitan area and you're comfortable with the ones you've got staying blue, you get down to cities like Lubbock and Amarillo (12 and 14th largest cities in the state).
Again, total speculation on my part.
I think the game plan for winning Texas is threefold. (In order of difficulty from easiest to hardest.)
1. Maximise turnout in Austin, San Antonio, Houston, El Paso, and Dallas.
2. Minimize the damage in places like Lubbock, Amarillo, Waco(Ha!) and Ft. Worth.
2. Tie the suburbs. Places like Collin County (Dallas) and Montgomery County (Houston). This is the hard one, but it's the one that Trump makes possible. You have to use his weakness with college-educated women to put a huge dent in the GOP's suburban block. That's really the heart of their power in Texas.
A field office in Lubbock makes me think that they are at least toying with something resembling this plan.