At some point, polling methods will have to adapt to the changes in technology and lifestyles. Let's face it, a lot of people don't have landline phone service at home and many others don't answer home phones unless (1) they know who is calling and (2) they feel like talking.
That means it's very likely that polls (at some time in the future if not already) will tend to over-sample people who still rely primarily on a landline and still answer their phone on a regular basis (I suspect that is mostly elderly folks).
So, I wonder when the prototypical polling methods will finally go over the cliff in terms of reliability and accuracy? Perhaps, it is already occurring.