I think a good Davis map would be the usual Democratic strongholds (Mexico border, San Antonio, Austin, Urban Dallas) plus a stronger margin in Houston County than other Democrats have gotten. Plus I'd expect her to do better in Tarrant Co. and the Corpus Cristi area.
Tarrant County is a good bellwether for the state as a whole, so I'd expect her to need to do well there in order to have a ghost of a chance.
Tarrant is a good average for an urban area in Texas.
She would need to cut into GOP support in the Amarillo and Lubbock areas, turning those from roughly 80-20 to 60-40, and run an Obama-style campaign in some of the outer-ring suburban counties of Dallas and Harris Counties (notably Denton and Collin Counties in the north and Fort Bend and Galveston in the south). Note well that the difference between Democratic successes in Northern states and Southern states is that in the North the Democrats have been doing well in the suburbs and Democrats have yet to do so in the South other than Florida, North Carolina, and Virginia.
She MUST get heavy Hispanic turnout.
