Corbett was not a particularly effective republican or conservative governor. He wasn't helped by the legislature which while it had a republican majority in both houses, most of those are really RINO's.
Add to that low information voters and a strong democrat majority in the Philly area. A lot of people in this state believe the propaganda about there not being any taxes on fracking or fracking being bad for the enviroment. In PA they use extraction fees instead of taxes, the local media parrots the Dems claims there are no taxes and refuses to acknowledge/report on the extraction fees.
A lot of people in PA don't like Corbett because they believed that either Corbett stalled prosecuting Sandusky or that he didn't do enough to protect Penn State from sanctions after the Sandusky thing. Or both. Penn Staters can be unreasonably idiotic about anything to do with Penn State.
Lots of other reasons, but basically Corbett was a mostly ineffectual governor who ran a bad campaign. All is not lost though, as long as we maintain the republican majority in the legislature, Wolf probably can't do to much damage.
