With ALL due respect what data set underpins your belief that Donald Trump will do even a single thing that he promises to do if elected? I can't seem to find that.
May I take a shot at the answer?
Trump's history. It's easy to look up in Google, Trumps' 40-year history in business is an open book. (But be wary of political analysis of Trump--those are suspect. Look in the trade publications. That's where you get unbiased analysis of Trump's past performance in the business community.)
When Trump announces to trade publications and to general public/media, that he plans on building a new skyscraper or shopping mall or golf course, and he gives the projected costs and completion date, guess what? The record shows he gets it done! Usually on time and on budget.
In other words, he has no history, none, zero, of saying he's gonna do something and then not following through. He makes a promise, he keeps that promise. People that work with him have all said that about him. By the way, there's also no record of any former employees of Trump saying negative things about him – and this is after a long career of hiring people, managing people, and running a successful business enterprise.
So, is that good enough for you? It is for me. If you want to see whether someone keeps their promises, look at the promises they've already made and kept as a guide post for future performance expectations.