Certainly, some of this is due to a population increase from people moving to Texas. That by itself would raise the unemployment rate, but on the other hand those people are consumers, too, raising demand and creating jobs. It's easy to look good when all you do is look at the jobs number. But if your unemployment rate is not that great then your society is not that great, even without getting into the high number of medically uninsured in Texas, the pollution due to a lack of regulation, and all the other dismal Texas social indicators.
PS: This great post from Political Math Blog has a more detailed, nuanced view of the numbers.