I think Needlenose's Iowa correspondent, fubar, may have inadvertently explained the problem. His
post from Des Moines yesterday had him chalking up
"Three 1's in one household," with "1's" being shorthand for committed supporters. How many of them showed up? How many enthusiastic, underexperienced Dean canvassers from out of state got a little carried away in identifying "1's" that were really only "2's" or even "3's"?
Further analysis at Needlenose, for anyone who's interested.