The election: Why the polls vary

last updated 8 January 2015

The Pew Research Center poll shows President Obama opening up an 8-point lead over Mitt Romney. The Gallup poll shows the race dead even, while other polls find small Obama leads. “What’s a poor voter supposed to believe?” said Doyle McManus in the Los Angeles Times. With just five weeks left before Election Day, respected polls are showing results that are all over the map. That’s because “political forecasting, like astrology and reading entrails, is a junk science,” said Matthew Continetti in FreeBeacon.com. All we can say for sure at this stage is that the race for the White House is still “a jump ball,” with the RealClearPolitics.com average of polls showing Obama with about a 3-point lead. That could easily melt away after the three upcoming debates, or because of some big news event or Obama gaffe.

That’s conservative wishful thinking, said Will Oremus in Slate.com. The polls that consistently find Romney doing several points better than the others tend to rely on automated “robopolls” to conduct their surveys. The law prohibits automated calling to cellphones, and so those polling firms are failing to reach the estimated one in three U.S. households that has no landline, including many young people and minorities—who tend to vote Democratic. Polls that do include cellphone users show Obama “well in front” of Romney, with a 4.1 percent lead nationally. Maybe so, said Jay Cost in the New York Post, but other polls have built-in biases, too, including how the pollsters screen for “likely voters,” and what proportion of Democrats and Republicans they include. The critical margin in this election will come from voters who are still undecided, “and when the polls are bouncing around a lot,” no one can really know who’ll win.

Still, the picture’s getting clearer, said Nate Silver in NYTimes.com. Obama has held a small but clear lead for weeks now, and with voters becoming more stridently partisan in recent years, they’re less likely to change their minds in the final weeks of a campaign. Obama’s current lead over Romney of 3 to 4 points “is not that impressive for an elected incumbent,” but since 1936 fully 18 of 19 candidates who have been ahead in the polls this late in the game have gone on to win the White House. A big swing toward Romney is still possible, but all the data give Obama about an 80 percent chance of victory.