The study identified what "triggered" something to become a story—was it a campaign event? Newsroom initiative? An accusation by a candidate? Or something from outside the campaign?

The answer is journalists, for the most part, decide what is news in campaigns. More than half of all stories, 56%, were initiated by journalists deciding to pursue a certain subject. For newspapers, four-in-ten of these pieces were editorial and op-ed columns, but the bulk of it was still news coverage.

Candidates and their campaigns succeeded in triggering a little more than a third (37%) of the stories.

These numbers, incidentally, are virtually identical to what we found in the primaries.