Results of a new poll carried out by NBC-WSJ-Marist were released on March 28. Participants from Iowa were asked, who they would give their vote to, if the election were today. Of those who responded, 48.0% said that they are going to vote for the Democrats, whereas 40.0% indicated that they would give their vote to the Republicans. This poll was conducted from January 2 to January 7, among a random sample of 1470 registered voters. Figures have a +/-2.6 percentage points sampling error.
Converting these results into two-party vote shares yields figures of 54.6% for the democrat Clinton and 45.5% for the republican Trump. The democrats did worse by 1.7 percentage points in comparison to the average results of the other polls in Iowa.