Nate Silver sizes it up. Money quote:

The Republicans have two candidates in Ms. Palin and Mr. Gingrich whose net favorability ratings are actually  in the double-digit negatives, something which since 2000 had only been true of Pat Buchanan and Al Sharpton.

Palin is the Sharpton of the far right in many ways. Buchanan is so much smarter and more honest than Gingrich.