Except the polls were pretty darn accurate in 2008 and that is what has some of us more than a little jittery this time around.
The polls were accurate because they saw a massive groundswell of Obamamania and gave him a +8 advantage with polling, which was correct. To still be giving him such an advantage today is borderline ridiculous.
SOME polls were accurate.
The polls by professional polling houses (Gallup, Rasmussen, ARG, SurveyUSA, etc.) showed a steady Obama lead for a month leading into the election. They were largely correct. MSM polls showed Obama with unsupportably huge leads (10-15%, when he actually only won by 7. These usually overstated Obama's support, and for much the same reason as they are today - messed up internal demographics and unrealistic partisan ID breakdowns.