Palin was not debilitated.
She laughed off the accusations against her no differently from how Obama and (Bill) Clinton did, because (as with those guys), the accusations were either false, unsubstantiated, or irrelevant in they eyes of a decisive majority of the public.
Palin CHOSE to move on to her media career rather than fight in Alaska, and she CHOSE to keep on her media career rather than run for President. Her choices in both cases were perfectly rational. Staying as Governor was costing her a lot and benefiting her little. Running for President would damage her media career and while being prohibitively unlikely to end up with her in the White House.