Nate Silver does a fascinating analysis of polls according to whether they include cellphone respondents or not (h/t Andrew Sullivan). Polls including cellphone calls show a much, much wider lead for Obama. Silver adds these comments:
"I did a radio hit the other afternoon with Mark
DeCamillo of California's vaunted Field Poll, which does include
cellphones in their samples. He suggested to me that it was much easier
to get the cooperation of cellphone users on the weekend than during
the week. How come? Because most cellphone plans include free weekend
minutes. Conversely, one might expect that young people are
particularly difficult to reach on their landlines over the weekend,
since they tend to be away from home more (especially on a weekend when
some nontrivial number of them are out volunteering for Obama). So,
while I haven't tried to verify this, it wouldn't surprise me if the 'cellphone gap' expands over the weekend, and contracts during the week."
