What's your hangup? Pew Research shows a decline in landline telephone use

Keep these numbers in mind when you hear about political polls as we head toward November elections. 26% of households do not have a landline, and are not likely represented in telephone surveys of "likely voters".

In the case of the landline phone, a rising thumbs-down verdict comes not just from the survey but also from the marketplace. According to a Pew Research Center analysis of government data, just 74% of U.S. households now have a landline phone.1 This is down from a peak of 97% in 2001.2
From the Pew Research report, The Fading Glory of the Television and Telephone

Well, who are they missing?

The latest estimates of telephone coverage, released last week by the National Center for Health Statistics, found that 25% of households (and 23% of adults) in the second half of 2009 had no landline service and only cell phone service (just 2% of households had no telephone service of any type). For certain subgroups in the population, the numbers are considerably higher: 30% of Hispanics are cell-only, as are 49% of adults ages 25-29.
From the Pew Research report, Assessing the Cell Phone Challenge

Wow, if you are hispanic and in your late 20's then it just looks like you are under represented in political surveys.
Before you start thinking this is an isolated situation, think again. The general trend is away from landlines.

(Pew Research, 2009)

Polls have a margin of error, depending on how many people are in the sample. The problem is that at some point very soon the polls will simply be wrong. You should anticipate getting a call on your cell phone in the near future. What the caller on the other end will not know is if you are standing in your home, or are driving down the road. The nature of the problem is that a perfectly reasonable landline activity will intrude in to your cellphone context, anywhere, placeless.
It will take years of society rule making to negotiate the right time/place involving a device whose killer app is its landline-ness-less.

It has taken a decade, or so, for a cell phone call to be an acceptable activity in some shared social spaces. Yakking on your phone at a fast-food restaurant when you are alone is pretty safe, unlike having your ringer going off in the middle of a movie theater during a movie.
Those calls are most likely you talking to somebody you know.

Now imagine it is a survey call on your cellphone.