Bush wouldn’t fire Hansen because he would have had to admit that there was something rotten in the state of Texas.
Hansen works out the Goddard Space Science Center - based up in Maryland. He has nothing to do with Texas, Houston, or other NASA offices.
Much of his (Hansen's) global warming propaganda is through his other full-time (government-paid) paid in the Columbia University.
Your reference to Texas and Bush (other than that Bush SHOULD HAVE fired him from his GISS position many years ago) is wrong.