Likely voter polls can not accurately measure a race with such odd dynamics. Early voting has increased 24% since 2002 which is the primary reason I remain optimistic.
This varies wildly by county. For the 15 largest counties, which represent 60% of the statewide vote, early voting was up 5.5%.
Fort Bend +46%
Collin +23%
Galveston +22%
Nueces +21%
Denton +19%
Harris +15%
Williamson +13%
Montgomery +11%
Dallas +6%
Bexar +5%
Tarrant -0%
Travis -7%
El Paso -20%
Hidalgo -29%
Basically you had a huge increase to vote against what's his name in TX-22; population growth in the suburbs, and a bid drop off along the border since Sanchez isn't running.