In the 2010 Senate races, 91 percent of incumbents won re-election, even in highly contested races in California and Nevada. Only two incumbents lost, Blanche Lincoln in Arkansas and Russ Feingold in Wisconsin.
One more surprise: Facebook and Twitter were less accurate at predicting who won the youth vote than the total vote.
Facebook correctly predicted 45 percent of the winners of the 18-to-29-year-old vote, and Twitter correctly predicted 55 percent of the races for which exit poll data on younger voters was available.
Young voters are much more likely than older voters to use social media. According to Pew Research, 86 percent of 18-29 year olds use social media.
"The effects of social media [on the youth vote] are hard to quantify. It's hard to imagine it wouldn't affect the vote. However, youth voter turnout has been really consistent since 1994," said Peter Levine, the Director of The Center for Information & Research on Civic Learning and Engagement at Tufts University.
Social media are also less reliable than survey and poll data, the current most accurate way to predict election results.
"This year, the polls were spot on," said Levine.
"People answer surveys sincerely," said Gellman. "If you support the Republican and you lie, you make the Democrat look better."
All Senate candidates in November used social media, with one exception: Democrat Jim Rogers in Oklahoma. Rogers did not have a website for his campaign. Rogers lost.
Many voters see Facebook as an important communication tool for interacting with candidates.
"Facebook will be the single most important communication tool of this decade. Politicians who realize this are forward thinkers, or at least good marketers... I would not vote for a candidate who did not have a Facebook and Twitter presence," said Chad MacDonald, a Facebook user from Los Angeles. MacDonald says he follows over 25 politicians on Facebook, and he's on the Twitter feeds of over 100 politicians.
"Liking" a candidate on Facebook is a sort of 21st century bumper sticker – a public reflection of who a person will vote for.
"I voted for the candidates that I 'liked' on Facebook if I was able to," said Facebook user Sharon Dwyer of Philadelphia, who said she likes six candidates on Facebook. "Some that I supported were not in my state so I could not vote for them, but supported them financially because they reflected my values and beliefs and I thought they would be helpful to our country."
According to Edison Research, 41 percent of Americans have Facebook profiles and 7 percent of Americans use Twitter. Eighty-seven percent of Americans know what Twitter is, and 88 percent know what Facebook is.
"[Social media] is interesting and promising…It is intriguing to think of social media as a new method [to predict election results]," said Levine.