There is a strong, very left element in Texas politics. You can see that in recent history by the Richards governorship. Moreover, the R legislators in Austin have on the whole, been less conservative than Perry. You can see that in the Bush governorship.
Overall, Perry has been steering the state in a generally conservative direction despite some powerful elements in the legislature. He isn’t nearly as weak as you seem to think, nor as perfect as some cheerleaders pretend.
Taken on balance, Perry would be a strong candidate (no one here doubts his campaigning skills), and at worst a pretty good President (e.g. he would probably make very good SCOTUS nominations).
I still prefer Bachmann, but I’m not going help Mittens by sliming Perry, Palin, or any other reasonably conservative candidate.
Even more recent than that. We still had a democratic-controlled state House in 2000.