This isn't about Pennsylvania specifically but it's part of the political conversation today. A new Pew study shows most statewide pollss -- like the kind we talk about here constantly -- do not include cell phone users, only those with landlines. Two years ago that created only a small bias in poll results, but it's since grown larger, and helping results (by 4-6 points) for Republicans.
Here's Pollster's Mark Blumenthal:
Since 2006, a rapidly increasing percentage of American households lacks landline phone service. The most recent government estimates find that one in four American households is reachable by cell phone only. Pollsters have been reluctant to sample and call Americans on their cell phones, partly because it costs more and partly because federal law requires hand dialing any call placed to a cell phone, which makes such calls less efficient and puts cell phone polling off limits to automated survey methodologies.
. . . The impact such a bias may have on this year's pre-election polls depends in part on the polls involved. At the national level, many organizations now routinely sample and call both landline and mobile phones. These include, in addition to the Pew Center, ABC News/Washington Post, AP/GfK, CBS News/New York Times, Gallup (both their daily tracking and the surveys in partnership with USA Today), Kaiser Family Foundation, McClatchy/Marist University, NBC News/Wall Street Journal and Newsweek.
At the statewide level, however, more expensive cell phone interviewing is far more rare. Except for a single experiment conducted by SurveyUSA this summer (involving live interview calls to cell phones) we have not seen any cell phone sampling or calling by the pollsters that use an automated, recorded voice methodology