Dial M for Margin of Error

Mark Blumenthal has an informative discussion of the problems cell phones pose to pollsters, While acknowledging serious problems looming on the horizon, he suggests that the current number of wireless-only households probably isn’t high enough to shift a poll dramatically:

Still, assume for the sake of argument that wireless adults are 5% of the electorate, that a survey of wired households shows a 48%-48% tie and that the missing wireless-only voters prefer John Kerry by a 20-point margin (58% to 38% – a pure but plausible guess based on the numbers for renters, low income, etc). If we were able to include the wireless only adults, it would change the overall preference by only one point – Kerry would lead 48.5% to 47.5%.