Take a look at what she is up against in AZ: The Swamp Stikes Back
As one senator of 100, which even if technically has a GOP majority her own caucus would likely still be RINO dominated. Or as governor of a swing state, with a solid GOP legislature ready to spit out not only Rats but RINOs. Fix AZ and its elections and a GOP president becomes conceivable. As one senator she can't do nearly as much.