One limitation of most polls is that they’re binary—they ask whether a vote will go one way or the other. Sentiment data, on the other hand, can tell politics watchers precisely why a candidate’s numbers are up or down. One example Rothschild cites is Rick Santorum’s fluctuating poll numbers. By tracking Twitter sentiment and search data, Rothschild and Pennock found evidence that this reflected a shift in focus: the public was at first interested in the candidate’s stand on homosexuality and race. Later on, voters were more likely to search for information about his economic policies.
“This can happen in hours or days, on a time scale you can’t see in polling,” says Rothschild. It’s possible that sentiment analysis will even yield insights into whether or not a candidate or an issue has staying power, or is merely a flash in the pan. Prediction markets already seem better than polls at taking the longevity of a trend into account—while Cain, Perry, and Trump all took turns at the top of polls, Intrade and other prediction markets monitored by the Signal always had Romney coming out ahead consistently.
So what do the brains behind the Signal predict for Saturday’s primary in South Carolina?
“The race is pretty much over,” says Rothschild. “At this point, Romney has over a 90 percent likelihood of winning the nomination, and of winning the South Carolina primary.”
And what about the general election?
“[The odds of Obama winning] have been consistently inching up slowly as the Republican primary has hit a crescendo over the past two months,” says Rothschild. Pennock, who crunches the numbers for the team, says their latest result puts the chances for Obama’s victory at 52.9 percent.