Des Moines Register, pretty interesting.
The paper did not ask who the voters in Iowa would vote for (a pretty meaningless question right now), but instead, do you have a favorable or unfavorable opinion of these politicians (all of them potential presidential candidates).
Republicans were asked their opinion of Republicans, while Democrats were asked what they thought of Democrats. But most interesting to me was when they asked all the poll respondents to give their opinion of all the candidates (regardless of party affiliation). That is more representative of what might happen in a general election.
The candidate who did the best was Hillary Clinton, who gets a favorable rating from half of the voters in Iowa. The second place finisher was Chris Christie, who finished about 6 points behind Clinton. He was the only candidate to finish less than 10 points behind Clinton.
But Christie must have gotten a lot of his favorable rating from Democrats (who would not vote for him in a general election featuring Clinton as the Democratic candidate), because he didn't do so well among Republican voters -- tying two others for fifth place (Bush and Paul), and finishing well behind Ryan, Huckabee, Santorum, and Perry. It looks like Christie has a lot of work to do if he's going to win in the Iowa caucuses, because the Iowa Republicans prefer candidates much farther to the right.
On the other hand, Hillary Clinton looks like a lock with Iowa Democrats (with an 89% favorable rating), and unless a lot changes, could well carry Iowa in the general election.