First of all, it is too early for any of the candidates to be considered worthy. Let them go through the trials of the primary season, see how they stand up, and then lets see. This time four years ago, everyone was talking about Giuliani, remember? He fell by the wayside quickly.
If Palin wants to prove herself, the path is open to her...but it will be a hard slog, and she will be challenged.
If Sara does decide to run, one of the biggest obstacles she'll have to overcome is the voters who will shy away from electing another "first"
After all, we're seeing how the "first" black man in office worked out.
Personally, I'm not sold on her yet either plus we still have a long way to go.