Among Republicans, it’s overwhelmingly Trump: 65 percent say the business mogul will win the GOP nomination, compared with 23 percent who named Cruz and 5 percent who named Kasich.Back in September the mercurial mogul signed a pledge promising to back the eventual Republican nominee, even if it wasn’t someone he sees in the mirror every morning. Cruz said, “I’m not in the habit of supporting someone who attacks my wife and children”.Cruz, referring to several tweets by Trump attacking his wife, made it clear that if Trump were the nominee, he would not support him.Mr Trump claims he has been “treated very unfairly” by Republican party leaders – some have expressed disquiet or downright opposition to him winning the nomination.”I don’t think there’s any question”, he says, “that John Kasich is continuing to run on what’s going to be a losing campaign in order to deny Donald Trump a majority of delegates heading into Cleveland”. “I don’t need their support”, Trump said.Cruz said if Trump were the nominee, that would hand the election to Democrat Hillary Clinton. “I love the Republican Party”, he added.Trump leads Cruz in the delegate chase, where Kasich lags in a distant third place. “But when you go after my wife, when you go after my daughters, that does it. And I think – I want this race to stay focused on policy and issues and solutions to the real problems facing America”.”No, I don’t anymore”, Trump told CNN’s Anderson Cooper, when asked if he remains committed to the pledge.Ohio Gov. John Kasich, also appearing on the CNN town hall, hedged as well. As recently as March 3, in a Fox News debate, all three said they would support the nominee. I don’t want to make people uncomfortable.If the nominee is someone I consider is hurting the U.S. I can not stand as one of his supporters. If Cruz wins, it would narrow Trump’s already tight path to the nomination and raise the prospect of a contested party convention.Mr Trump also defended his campaign manager Corey Lewandowski, who was arrested by Florida police and charged with battery for allegedly grabbing a reporter at an event earlier this month.