The US, including Texas, continues to suffer economic difficulties stemming from the Great Recession (2008-present).
Withdrawing from the US is unlikely to help Texas' economic recovery; in fact, it will likely impede it due to political uncertainly and negative effects on intra- and inter-state commerce, education, and other industries.
A few examples: domestic flights will not be routed through major airport hubs in Dallas and Houston; universities and businesses will find it difficult to recruit high-caliber employees from outside the state; national businesses headquartered in Texas will move their main offices; US citizens' insurance will not cover our cutting-edge hospitals (e.g., MD Anderson); NASA will leave.
Our economic recovery depends on working together as a nation.