Not to impugn the Donald, but I am doubtful that this pledge will be worth the paper its written on if Trumple falls in the polls sufficiently to cost him the nomination. Since it isn't legally binding it's just a nice thing until Trumple's options decrease.
Trump knows he's got a strong base that will not be swayed by facts or common sense, so if he fails to get the nomination because the GOP accidentally gets an influx of people who actually think about their nominee I'm guessing he'll simply tear up the pledge and run 3rd party. I mean it's only rational if everyone else on the planet who disagrees with Trump is a "loser".
Why wouldn't Trump want to provide the people of earth a "Winner"? Just because of some little piece of paper? Ohmy!
