One distinct disadvantage which Obama had in the US presidential election campaign was that Democrat voters weren't as solidly behind him, while many more Republicans backed McCain. In August, Reuters/Zogby showed only 74% of Democrats backing Obama, with 81% of Republicans backing McCain.
Sarah Palin has changed all that.
Yes, she has swung more Republicans behind McCain - so that 89% of them now back McCain, according to the same polling organisation.
But gues what? She has had an even greater effect in swinging Democrats behind Obama, so that he also has the support of 89% of his party's voters!