A new survey from Evolving Strategies, a Republican polling firm, has determined primary preferences among GOP voters are “unstable” and “susceptible to small changes in information.” Conducted between December 6 and 8, the survey found that Newt Gingrich is “highly vulnerable to attack” from opponents and that Mitt Romney’s negative aspects appear to be already “priced in” to how primary voters view him.

The survey, unique among firms examining the Republican primary, incorporates experimental data that examines the effect of campaign ads on support for candidates. The 672 Republican and Republican-leaning respondents were divided into three groups: a “Gingrich condition,” a “Romney condition,” and a control group. Those in the Gingrich condition watched, in random order, a positive and negative campaign ad each about Gingrich and Rick Perry; the Romney condition similarly watched four ads, positive and negative both for Romney and Perry. The control group watched a non-political advertisement.