https://fivethirtyeight.com/features/how-the-republican-field-dwindled-from-17-to-donald-trump/
Except for Trump, all the contenders were pols who likely provided plenty of fodder. And the MSM would have happily sat on any stories waiting for Hillary to say when to publish.
The only drawback to that scenario is that Trump was not some unknown. He has been living in the public eye for decades; if there were any dirt on him, the tabloids would have picked up on it eons ago. Many of the Republicans in the candidate lineup had little name recognition and did not live public lives (political careers notwithstanding).