The percentages reflect difference between prediction and outcome for each polling outfit in their last poll before the Iowa caucus. I didn't do an examination of each poll but based upon sample size the MOEs should have been around 4-4.5%. All the polling companies blew the turnout models pretty badly. It's not the end of the world - so did the Romney and Clinton campaigns, with Clinton blowing it worse than Romney.
How did Obama get under the Clinton radar? I understand Romney missing Huckabee's use of the informal church social network to clobber him but Obama just took the Dean/Kerry appeal to first timers and ran it better than either one did in '04. Clinton got sandbagged - good for Obama.
CNN has the absolute worst performance with ARG coming second and Strategic Vision third. The Des Moines Register did best and Zogby and Insider Advantage were mediocre.
Rasmussen was wise to stay out of this one.
I think I'll do this again after New Hampshire to see if there's an improvement.