Silver studies Palin's path through the 2012 GOP primaries. The red states above are more favorable to her, the blue ones less so:
Among the first four states to vote, both Iowa and South Carolina should be winnable for Palin. Although Iowa is not a perfect match for her -- not quite as many no-college voters as she'd like -- it holds a caucus rather than a primary, which tends to bring out a more conservative electorate. The most obvious concern for Palin in Iowa, if he runs, is Mike Huckabee, who won there in 2008. She could also conceivably lose a war of attrition if a candidate like Santorum eats away some of her evangelical vote, or if her organization and infrastructure is not up to par. The inclusion of a regional candidate like John Thune or Mike Pence could cut either way for Palin; they are not yet terribly well defined and it's unclear whether they'll run to the right-center (in which case they could cause more problems for someone like Romney) or further to the right (trouble for Palin).