A new post-Caucus Survey USA poll of Iowa registered voters shows, among other things, Obama trouncing all Republicans (especially Rudy). The highlights:

Obama defeats McCain by 17 points. Obama defeats Huckabee by 23 points. Obama defeats Romney by 26 points. Obama defeats Giuliani by 40 points. McCain defeats Clinton by 4 points. Huckabee and Clinton tie. Clinton defeats Romney by 8 points. Clinton defeats Giuliani by 16 points.