...image of a feisty and somehow loveable underdog.

Not hardly. By the end of the campaign her own party leaders were shaking their heads and distancing themselves from her. I think she and McCain came out of right field at them and they didn't know what hit them, BUT they figured it out and only the very conservative, evangelicals of them would support her now. I don't think they'd even use her as a front because they obviously could not control her.