That’s a nice sentiment and in most cases I would agree.
But Trump is not most cases. He’s an outside agitator running as a caricature of a conservative.
Trump has done a good job of staying consistent for five years! Perhaps it's hard to live in NYC, deal with the liberal government machine Trump has to deal with, and still learn to articulate conservative positions smoothly. I'll agree that he has not thought all the issues through in as much detail as I'd like, but Trump has been consistent for several years:
http://www.ontheissues.org/Donald_Trump.htm"
He's as good a bet as just about any candidate - with five years of reasonably consistent positions. I remember US Senate Candidate Rubio and how that promising conservative turned out. So, yes, Trump could be lying. But he could also be telling the truth. I am certain that Hillary, Bernie, Jeb, Kasich, and Rubio are all telling the truth with their Amnesty promises to betray America on immigration. I'd far rather take the chance that Trump (or Cruz) might be lying on a particular issue than settle for the certainty that Hillary is telling the truth.