Such rumor emerged as early as one year ago, but for now I increasingly feel it might be true, otherwise how can we simply regard all the following things as coincidence?
Trump gained overwhelming popularity in 2015, which made him the nominee of GOP. However have you noticed that his reputation suddenly plummeted shortly after his nomination was formally confirmed, as if he acted on purpose.
At this last debate, it appears the best and last chance for Trump to save his fate. But in the end, unexpectedly (or as expected) he refused to accept the election result. Who on earth would do so if he seriously wants to run? I mean even a 5-year-old knows how to answer that question in that case.
If Trump had behaved like this one year ago, he wouldn't become a nominee. In other words, his nomination largely eased Clinton's pathway to the white house.
Trump greatly helped Clinton & Democratic, regardless of the reason.