So was there any good news for Clinton or Edwards? Not much. Clinton won (barely) among married people; among rural voters; and among the elderly. Edwards won among conservatives (!) and the middle-aged. I think Edwards is doomed now, since he just doesn't have the money to overcome this loss. Clinton isn't, but I don't know if you can say much more than that. Obviously she has a tougher road now against a well-funded Obama campaign with lots of momentum, but I wouldn't be willing to say much more than that.
Among Republicans, the picture is obviously a lot muddier. Huckabee's victory was also impressive, winning among both men and women; among evangelicals; among Bush lovers; among every income group except the well off; among all issue groups; and among all age groups. Romney won only among moderates; the well off; and urban voters. The rest of the field was nowhere.
But I just don't believe that Huckabee is going to be able to sustain this. Iowa's Republican turnout was 60% evangelical, and I don't see him being able to broaden his appeal in less God-soaked states. But we'll see.