http://www.washingtonpost.com/wp-dyn/content/article/2008/10/31/AR2008103103044_2.html?sid=ST2008110101102&s_pos=
"I worry more about a basic concern: whether we are getting a truly random
sample of opinion. Pollsters bank on the fundamental notion that the people
who answer our calls are similar to those who don't, and we have reams of
data justifying those assumptions. But what if the people who pause to take
a pollster's question are significantly different from those who don't?
After all, fe