Free media is less helpful to Trump in Iowa

Two patterns jump out here. First, Ted Cruz and Ben Carson (the black and red dots, respectively) were able to get to Trump-like levels in the polls without nearly as much national media coverage. Second, increasing Trump’s share of national coverage has diminishing returns in Iowa. In other words, his Iowa poll numbers on days when he received 60 percent of national media coverage look pretty similar to his standing on days when he received 30 or 40 percent.

So what makes Iowans so different from other Republicans?

First, Iowans aren’t just hearing from national media. Campaigns are attempting to reach potential caucus-goers by airing local television ads, holding rallies, sending direct mail, placing phone calls and deploying volunteers to knock on doors throughout the state. In other words, Iowans have sources of information other than the national media.

Second, Iowans are faced with something that national audiences aren’t – a fast-approaching election. They are beginning to tune in and take a hard look at their choices because, unlike Americans nearly everywhere else, they get to vote in the immediate future.