It's well documented that Sarah Palin has problems with Democrats and independents, but the first seven states where we've looked at the 2012 Presidential election make it clear that she has a Republican problem as well. It's not that Republicans don't like her- on our last national poll 68% rated her favorably, making her easily the most popular prospective 2012 candidate with Mike Huckabee at 63%, Newt Gingrich at 57%, and Mitt Romney at 56%. It's that a lot of the Republicans who don't like her- in contrast to the Republicans who don't like Huckabee, Gingrich, or Romney- aren't willing to hold their nose and vote for her in the general election.
Across the 7 individual states where we've done 2012 polls so far- Michigan, Minnesota, Missouri, Massachusetts, North Carolina, Montana, and Virginia- Palin averages receiving 77% of the Republican vote against Barack Obama. That puts her slightly behind Gingrich at 80% and well behind Romney and Huckabee at 84%. Palin does the worst of the Republicans among Republicans in Montana, Missouri, Massachusetts, Michigan, and Minnesota. Only North Carolina where she does better than Romney and Virginia where she does better than Gingrich and Romney serve as exceptions to the rule.
Republicans may hate Barack Obama but there look to be a pretty meaningful percentage of them who don't hate him enough to vote to put Sarah Palin in the White House. When you combine that with her complete lack of appeal to Democrats and independents she looks virtually unelectable for 2012.