The balance of public opinion is decidedly against a Sarah Palin run for president. Nearly two-thirds — 64 percent — flatly rule out supporting her in 2012; 28 percent would consider it; and just 7 percent are committed to voting for her.

In the Republican former governor of Alaska decides to join the race, the numbers leave a lot of convincing ahead, even within her base. Across a variety of Republican-aligned groups, there is steep opposition to Sen. John McCain’s 2008 running mate.

Among Republicans overall, 42 percent would definitely not vote for her, and 14 percent say they would definitely support her. Palin was in a better position among Republicans in 2009 and 2010, when fewer than three in 10 flatly rejected her and majorities said they would consider voting for her.   

Sentiment among conservatives has shifted 10 percentage points away from Palin since 2009; now 46 percent would not vote for her. Conservative Republicans are not as sharply negative, with 37 percent saying they wouldn’t vote for Palin. But that has moved 17 points away from her in since 2009.

Almost half of white evangelical Protestants would definitely not vote for Palin – a group that’s been warm to her previously. In 2009, only one-third said they would not vote for her.

Fully half of strong tea party supporters would at least consider voting for Palin; 25 percent would definitely vote for her; and 22 percent would not vote for her. This is the only group for which – numerically – more people would definitely vote for than definitely not support her, although the results are within the margin of error.