The irony of the two states historical political party strength is that Texas has elected more Democrats at both the state and national level, than California has.
Since Texas doesn't register by party, it's more difficult to find trends, but the way Texas is being swamped with illegal aliens and how migration into the state is generally occurring (more growth in liberal big cities), it is not unreasonable to think Texas could go back to being blue in the near term.
Texas Population Projections 2010 to 205
https://demographics.texas.gov/Infographics/2017/UrbanTexasPt2