Republican presidential nominee Sen. John McCain invented cell phones.OK, so maybe he didn’t actually invent cell phones — even though he kind of, sort of, basically said he did — but a new study by Pew Research Center may make McCain wish he had nothing to do with the creation of cell phones at all.According to Pew, some presidential horse race polling could be underestimating support for Democratic presidential contender Sen. Barack Obama by about two to three percentage points because of cell phones.Obama has undoubtedly attracted a large and enthusiastic base of young voters — many who are engaged for the first time. This youth support is coupled with, according to Pew, a rise in the number of people who no longer use landlines and can only be reached by cell phones, which presents a problem to pollsters.Polling is generally conducted over landline phones — cell phones are hard for pollsters to reach. With the number of cell-phone-only users growing, not accounting for their presence might be skewing results.According to Pew, a “significant minority” of cell phone only users are young voters, and they are more likely to support Obama than McCain.When Pew conducted three separate surveys during the course of the election, the surveys that included cell phone respondents “resulted in slightly more support for Obama and slightly less for McCain, a consistent difference of two-to-three points in the margin.”While this may not initially sound like a significant percentage, keep in mind recent presidential elections have all been decided by relatively small margins. A difference of two or three points means that McCain — even at the climax of his convention bounce — may have never actually led Obama at all.Pew is not alone in their conclusion. Nate Silver, a polling analyst who runs FiveThirtyEight.com, found a similar bias — about two to three points — when he conducted a study of 37 different pollsters.Though young voters are sometimes thought to be largely disinterested and AWOL on Election Day, Pew found that, this year, young voters are just as enthusiastic as their older counterparts.”While 18-29 year-olds reached by cell phone tend to have less experience voting than their landline counterparts, they are just as interested in the 2008 campaign, and express just as much intention to vote this year,” the Pew study said.Pollsters, though, do weight individual surveys by various demographics to ensure representation.Mark Blumenthal, another polling analyst who runs Pollster.com, says the conventional wisdom among pollsters in the 2004 Presidential Election was that weighting surveys by age could compensate for any potential polling bias.In 2004, that assumption appears to have been correct — the cell phone effect had, at best, a marginal effect on polling despite some speculation cell phones were Sen. John Kerry’s ace in the hole. Pew, though, has found evidence that even adjusting surveys and weighting for demographics may not sufficiently compensate for the cell phone effect in 2008. “Traditional landline surveys are typically weighted to compensate for age and other demographic differences, but the process depends on the assumption that the people reached over landlines are similar politically to their cell-only counterparts,” the Pew study said. “These surveys suggest that this assumption is increasingly questionable, particularly among younger people.”While it’s heartening to learn that young voters — so often perceived as unreliable – have seemed to tune in to this election, there is an even larger point.Polling, even at its best, is an imperfect science. At its worst, polling can be flat-out wrong. We are presented with polls all the time. The media seem to like close elections — undoubtedly driven by, at least, an economic interest in them — and what better way to illustrate a close race than poll numbers?CNN’s “Poll of Polls,” a clumsy mishmash of five separate pollsters’ surveys, is touted each week. Every other major network boasts its own polling, complete with their signature polling “analysts,” as well.Gallup, Rasmussen Reports and many other pollsters run daily tracking polls. Dozens of state level polls are released every day.Talk about information overload. Which of these polls are reliable; which ones can we trust?”It is getting more difficult to talk about standard indicators,” said Robert Goidel, director of Public Policy Polling for the Reilly Center. Goidel said random sampling, sample size and weighting demographics are all general indicators of reliability — though random selection is the most important. “Tracking polls can tell us something interesting about       movement in support,” Goidel said. But no single poll, removed from the context of others, can provide an accurate snapshot of the race.The whole picture is stronger than any one of its parts, but you won’t get the whole picture on “The Situation Room” or “Hannity and Colmes.”So try a little research on your own — it’s not hard, I promise.  —-Contact Nate Monroe at [email protected]