As Greenwald notes in this SurveyUSA , the Palin speech went over well with the public despite the negativity and mocking.
When will Democrats have the spine to fight fire with fire???
Glenn Greenwald - Salon.com
"But the idea that Americans instinctively recoil from negativity or that there will be some sort of backlash against Republicans generally and Palin specifically because of how "negative" their convention speeches were is pure fantasy. Cultural tribalism and personality attacks of those sort work, especially when they're not aggressively engaged.
Every four years, the GOP unleashes unrestrained personality attacks on Democrats and exploits cultural resentments. Every four years, Democrats tell themselves that such attacks don't work and are counter-productive. And every four years, that belief is disproven. These "character" issues end up mattering largely because Democrats, in election after election, allow wars over "character" to be waged in a largely one-sided fashion."