NYTimes -- Cellphones and Caller ID Are Making Pollsters' Jobs Harder

Pollsters said they might be undercounting the growing number of younger voters who only have cellphones, as well as elderly voters who, they said, tend to be especially wary of any call that sounds like a solicitation. Several pollsters said the rise in the number of unlisted telephone numbers was more pronounced in minority and low-income neighborhoods.

In a case that drew much notice over the weekend, two polls trying to measure the Senate contest in Minnesota produced opposite results: one had Walter F. Mondale with a six-point lead, while the other had Norm Coleman with a six-point lead.

Howard Wolfson, the executive director of the Democratic Congressional Campaign Committee, said he had seen instances this year where two polls by different pollsters in the same district had produced findings so different that it was as if they had come from different states.

As Dick Morris says, telephone polling has gotten a Republican bias.