It would seem to me, and I would argue to most reasonable people, that what someone says when they have nothing to gain - or lose - is the more sincere. Which puts the lie to Trump's current campaign positions, or at the very least would argue he has no sincerely or deeply held beliefs other than wanting to advance himself.
Back in a prior campaign, Howard Dean was called a flip flopper for changing his positions, to damaging effect. He had fewer of those positions than Trump has.
I have long harbored the secret suspicion that Trump is simply appealing to those who like the vulgarity of reality television, the same crowd the ancient Romans appealed to with bread and circuses displaying horrific violence in the name of entertainment. On some level, the modern voters must know that Trump is not real, at the same time they praise him for speaking 'truth'.
I actually had a debate on line where some moronic Trump supporter tried to argue that reality tv was powerful real-world stuff, and that Trump was demonstrating some sort of alpha prowess and potency that people would understand made Trump powerful. His argument was based on the notion that "tapping ass" (pardon the crudity) created some sort of jock-status back in high school. This moron had a difficult time grasping the notion that high school locker rooms were not the real world either.
However that might offer a glimpse into the emotional thinking that has made Trump popular primarily among lower educated and less evolved white males to the exclusion of other demographics. Trump voters are not only as a group less educated, but have never really gotten beyond that level of thinking and wishing.
In that context it will be interesting to see how well a belief in Trump's misogynist, homophobic, Islamophobic positions will survive seeing Trump's real world words from his past. What this should challenge is if wishful thinking will win or lose against a dose of reality. The other side is running similar campaigns against Hillary, but they are using more deceptive editing methods to misrepresent her past words.