Last year Donald Trump signed a pledge saying he’d back whoever becomes the GOP nominee. Now he doesn't think he will.

"No, I don’t anymore," Trump told Anderson Cooper at a town hall-style event hosted by CNN last night. "No, we’ll see who it is."

In September, Republican Party leadership asked Trump to sign a loyalty pledge at a time when he was threatening to run as a third-party candidate if he failed to capture the Republican nomination. Trump vowed to sign only if all of his Republican rivals did the same – which they all did.

But in November, several months after signing the pledge, Trump caveated his promise.

"I will see what happens. I have to be treated fairly," he said on ABC’s This Week.

Now it appears Trump has concluded he is indeed not being treated fairly. The frontrunner pointed to intensifying efforts to prevent him from winning the nomination despite a commanding delegate lead over rivals Ted Cruz and John Kasich.

"I have tremendous support right now from the people," he told Cooper. "I have many more delegates than him," he added, referring to Cruz.

When Cooper pointed out that Cruz hadn’t pledged not to support Trump – toeing the line, but not crossing it – Trump shot back that Cruz was under no obligation: "He doesn’t have to support me."

Cruz, faced with the same question, dodged it by saying such a situation would not come to pass – because he intended to be the nominee himself.

And Kasich said if the nominee turned out to be someone who "is really hurting the country and dividing the country," he simply wasn’t sure. He declined to say whether the divisive nominee he had in mind was Trump.