Ponca City writes "A good deal of polling data suggest that Republicans may win the House of Representatives in today's mid-term elections. However, Nate Silver writes in the NY Times that there are several factors that could skew the election, allowing Democrats to outperform their polls and beat consensus expectations. Most prominent is the 'cellphone effect.' In 2003, just 3.2% of households were cell-only, while in the 2010 election one-quarter of American adults have ditched their landlines and rely exclusively on their mobile phones, and a lot of pollsters don't call mobile phones. Cellphone-only voters tend to be younger, more urban, and less white — all Democratic demographics — and a study by Pew Research suggests that the failure to include them might bias the polls by about 4 points against Democrats, even after demographic weighting is applied. Another factor that could skew results is the Robopoll effect, where there are significant differences between the results shown by automated surveys and those which use live human interviewers — the 'robopolls' being 3 or 4 points more favorable to Republicans over all. It may be that only adults who are extremely engaged by politics (who are more likely to be Republican, especially this year) bother to respond to robocalls. Still, when all is said and done, 'more likely than not, Republicans will indeed win the House, and will do so by a significant margin,' writes Silver. 'But just as Republicans could beat the consensus, Democrats could too, and nobody should be particularly shocked if they do.'"