In Iowa, in the GOP race Ted Cruz has the Big Mo, having overtaken Trump, leading now by 31-28. There is reporting that Trump has no meaningful organization in Iowa (also NH for that matter.) Couple that with the fact that Cruz is supported by the most committed supporters in Iowa, the evangelicals, and I would not be surprised if this turns into a Cruz blowout.
Clinton's lead in Iowa over Sanders is currently 52-37. Personally I think any Clinton win in Iowa, even by a point, effectively ends the race. One of the reasons is that the expectation is Sanders is going to win New Hampshire, With that expectation, Sanders won't have much of a chance to change the dynamics in the race. The next 2 contests after NH are South Carolina and Nevada, where PC will be the dominant voter groups. After that you move to Super Tuesday on March 1 and that will probably close all drama.
Sanders has raised an amazing amount of money (and so has Clinton over 112 million so far) so he'll be in it to the convention, but he'll have no chance for the nomination unless things change before Super Tuesday.
For now, the suspense appears to be in the GOP race. After Iowa, NH has Trump in the lead with 26 percent (with Cruz, Rubio and the rest bunched together around 14 percent) but it would not be in the least surprising if Trump collapsed after losing Iowa. In theory NH is where the GOP Establishment first flexes its muscles, but the reality it's a battle for 3rd right now, with Rubio, Christie, Bush and Kasich duking it out. In theory 3rd (behind Trump and Cruz) gives them a lift. I'm skeptical of this theory as South Carolina comes next - I see that as Cruz country.
What about Trump you might ask? Well, imagine Trump losing Iowa and then losing NH. Can you imagine his meltdown? It could be epic, the moment of the primaries. And if Cruz sweeps Iowa and NH - I'd call ballgame. He'd win South Carolina, have the money flowing and the message (the crazy one) that the GOP base wants this year.
So in sum, if I had to choose today who I think is gonna win - I have Clinton and Cruz.Obviously Clinton is the stronger prediction and the GOP race can still provide many surprises, but that's where I see them right now.