Again SJP, you "assume" the nomination is won on what basis ?
Palin has gone after what every base of support she had left in the Republican party. The little support remaining will leave as soon as another candidate jumps in with a mightier bank account and better crowd pleasing talking skill ( which will not require much ).
Mainly because she is very popular with the Republican base, with tea party attendees, Francis. These are the people who vote in Republican primaries in large numbers. So I think Palin has a good chance of winning the nomination if she runs. I think there are about 30% Americans who think she will make a good president, and most of them belong to the Republican base.
Now, getting 30% vote in the general election means getting crushed by a landslide, but getting the same vote in the primaries could very well mean winning the nomination.