I'm not in the mood to defend George W. Bush, but I suspect that historians will eventually figure out that his big domestic / economic policy mistakes (e.g., allowing so much illegal immigration and promoting zero down payment mortgages to increase minority home ownership) stemmed from him assuming that the rest of the country was like Texas.
Bush had been a decent governor of Texas for six years. And Texas has continued to do relatively well in the eight years since he left Austin (e.g., there was hardly any Housing Bubble in Texas).
Bush knew Texas well, but he didn't know the other 49 states, especially not California. Approaches that worked okay in Texas proved disastrous elsewhere.