Back during the first GOP (aka Republican) debate, the candidates were asked the following:

"Is there anyone on stage, and can I see hands, who is unwilling tonight to pledge their support to the eventual nominee of the Republican party, and pledge to not run an independent campaign against that person?" 

Amongst noise and chatter from the audience, Donald Trump raised his hand with a smirk. #SorryNotSorry

Basically, this means that if he doesn't get the vote from Republicans, he would run against the Republican who does get the vote, which would likely separate the Republican voters, granting the Democratic nominee an almost surefire "W" for the White house.

Way to kick off the night, right?

Well, just a few days ago, on Thursday, Sept. 2nd, Donald took it back and agreed to sign a pledge to support whoever wins the nomination.

What inspired this change of heart? Who knows. Can he take it back again? You betcha. Although he claims that he has no intention of changing his mind, this document isn't legally binding, it's just a "political document."

And what's politics without a little back and forth?