Chris Roach has an essay about Texas that's well-worth reading.
A couple of things to keep in mind:
Since the first oil gusher in Texas 110 years ago, Texas has benefited from a whole lot of competent Americans moving in. The oil industry brings in people who can get stuff done. At least as far back as 1960's Project Talent national post-Sputnik tests, Texas schoolchildren were outscoring California schoolchildren, despite California having a lot more Nobel Prize winners.
Being governor of Texas isn't that hard of a job. It has an odd constitution where the Lt. Governor is surprisingly powerful.
Perry and Bush hate each other, but Perry seems like the guy Bush was always pretending to be.