As luck would have it, we were just kicking this question around the newsroom yesterday, then The Huffington Post writes about it: In an age when up to one in four American households has dumped their landline phone in favor of a cell phone-only lifestyle, are we reaching a tipping point when it comes to the validity and accuracy of largely landline-based phone polling?
A new study by the Pew Research Center says yes, and the advantage in landline polling is apparently slanted toward the Republicans.
Over the last four years, Pew conducted political surveys, taking "separate, parallel samples of both landline and mobile phones." During the 2008 presidential election, they found that the already-accelerating landline dump was producing a bias of 2.3 percentage points in favor of John McCain. Two years and a lot more ditched landlines later, and the effect is even more dramatic: a four to six point bump in favor of Republican candidates and Republican issues.
Yes, cell number databases are growing, and there are more people getting polling calls on their cell phone every day (I don't know about you, but when an unknown number comes up on my phone, I often let it shuffle to voice mail). The point, however, is that in a world where a five point swing in the polls on a given race or issue can send even the most stouthearted politician into a panic — and a bigger swing can send voter morale into the basement — it's a real issue, and one that appears to be growing.