Not true, under the right circumstances. The next very painful four or eight years will create the right circumstances.
In addition to that she is a very damaged good right now and she knows it.
No, the Republican Party is very damaged right now, and everyone knows it. And that's a good thing, because it has become a rotting corpse. The more mud the crypt-keepers throw at Palin, the further she is distanced from the stench.
And this certainly doesn't look like irreparable damage, where it matters most:
69% of GOP Voters Say Palin Helped McCain
Don't underestimate Sarah Palin.