Dunno, I think Mitt did as good a job as possible of stepping into the “severely conservative” shoes.
I do think he waited too long to come on strong, though. Even fiscally, if he was wobbling on social issues. For most people it WAS “the economy, stupid.” And Mitt had credible answers. But he evangelized them for too short of a time, while failing to point out what a mess a second, lame duck iteration of Barack would make.
Problem was those shoes were 10 sizes too big and did not fit Mitts career liberal feet.