… This year, Republicans believe that Democratic pollsters are relying too heavily on the 2008 turnout models, that the samples showing Democrats doing well in key districts include more minority and younger voters than those who will actually turn out.
Democrats think Republicans are too wedded to the 2010 models and are missing legions of new voters who will be motivated to come out to vote both for President Obama and Democrats down the ticket.
The slight differences in sample size can add up to dramatically alter a top-line result. [cont.]
Reid Wilson, National Journal