If Donald Trump plans to be the GOP presidential nominee, he will need to start uniting the party, Meghan McCain said Wednesday, but even that doesn't mean she's gotten over what he said about her father when his campaign first started."I'm sick of saying this on this show, but until Donald Trump apologizes to my family, I will have issues," McCain, a Fox News correspondent and daughter of Arizona Sen. John McCain, said on the network's "Outnumbered" program Wednesday."I'm old school. I'm from Arizona and he said a lot of crap about POWs," she continued. "Until he becomes the kind of leader I want to get behind, which means uniting all of the Republicans...it is still a hard sale for me."Back in July, during one of Trump's first appearances as a candidate, Trump slammed the senator's war record and called him a "loser" because he'd been captured and held as a prisoner of war. However, the week before, McCain described Trump supporters at a July 11 rally in Phoenix as "crazies."McCain a few months later said he'd back Trump if he becomes the GOP nominee, and that he doesn't feel that the front-runner owes him an apology, but that he does "owe an apology to every single veteran who was captured and was a prisoner of war."On Wednesday, though, his daughter said that if Trump becomes the nominee "fair and square, gets to 1,237 delegates needed, that is the will of the people. That is what people want."But at the same time, she thinks a Trump nomination would be "incredibly detrimental" to the Republican Party and to the Senate, and she is worried about what will happen.McCain said that Trump also has to start taking the election seriously if he wants to be the president."We have to stop treating the election like there is a Roswell landing-like conspiracy on both sides," she said. "If the, quote, 'establishment,' had this much power, Jeb Bush would be the nominee right now. I think that rhetoric also plays into something people like me are saying 'really?'"And at this point, if Trump is to be the nominee, it's time to "be the leader and get rid of the "kid stuff conspiracies," McCain said.However, that doesn't mean she is quite sold on Ohio Gov. John Kasich, either."John Kasich is helping Donald Trump easily," McCain said. "He's running fourth in a three-man race. "I'm trying really hard; I want to like John Kasich," said McCain. "I just don't. I'm a more moderate Republican. There is no logical reason for this man to be staying in the race except for ego."