Not to get too bogged down in moral and ethical dilemmas, but the "pledge" was meant to be a unifier for the GOP, around certain policies and values. Trump clearly does not believe in them, nor does he have any set values or beliefs that I can discern (certainly none that cannot quickly be changed for opportunistic reasons). He is not GOP nor was he ever going to be.
Kudos to Kasich (and others), who recognized this, and who saw how much his divisiveness and entertainment reality show was an abomination of the normal primary election process. If I had to say it from a legal and ethical standpoint, Trump's conduct and comments nullified any so-called pledge.
I am just sorry that Kasich did not stay in, as there could have been a real fight, now that Trump's ineptness is clearly coming out.
the pledge was explicitly built around every candidate following it. the minute one of them pulled out, it became null and void.
Really? Tell me what part of the pledge supports that thought (especially since you use the word "explicitly"):
http://www.nytimes.com/interactive/2015/09/02/us/politics/document-the-republican-national-committee-presidential-loyalty-oath.htmlThe pledge is as straightforward as possible, affirming that the losing candidate will support the party's nominee no matter what. There is no ambiguity or fine print that enables a losing candidate to break the pledge if the nominee is bad or if someone else breaks the pledge first. In fact, the pledge pointedly says, "regardless of who it is," which indicates that bad candidates must get support too.
You're just mis-characterizing the pledge in manner that fits your defense of Kasich.