Meghan McCain on her father's cancer battle, 'The View' and why she wants Trump to apologize

Meghan McCain has never been one to keep her opinions to herself.

These days, the outspoken daughter of Sen. John McCain, R-Ariz., is firmly holding down the conservative end on ABC's "The View."

As a young Republican, Meghan McCain is in what some might call hostile territory.

"Joy [Behar] is the most liberal person I've ever met in my entire life," she told ABC News' "Nightline." "I'm definitely the lone conservative."

The eldest of five children, the 33-year-old has been in the political spotlight most of her life, tagging alongside her father for both of his presidential campaigns in 2000 and 2008.

On "The View," Meghan McCain has the daunting task of explaining -- and at times defending -- President Trump.

"I feel like Jane Goodall interpreting, because I have so many friends of mine at home in Arizona. You know, they don't make a lot of money. They love Trump," she said. "They don't think that the people in the media understand them -- and I wouldn't say I 100 percent understand it -- but I think I have made a real conscious effort to understand it."

While Meghan McCain may stick up for Trump, he doesn't seem to return the favor. At this year's Conservative Political Action Conference, Trump renewed his attacks on her father.

Trump didn't specifically name the Arizona senator during his CPAC talk Friday, but he alluded to him, criticizing the "thumbs down" McCain made while voting against the Republican health care repeal plan.

"Boy, oh, boy. Who was that? I don't know. I don't know. I don't know. I don't want to be controversial, so I won't use his name. OK? What a mess," Trump said during his speech.

Cindy McCain, Meghan McCain's mother and the senator's wife of nearly 38 years, took the president to task when she was a guest on "The View" last week.

"We need more compassion. We need more empathy. We need more togetherness in terms of working together," Cindy McCain said. "We don't need more bullying, and I'm tired of it."

Trump also made comments while on the campaign trail about the war hero, who was shot down and taken prisoner during the Vietnam War.

"He's not a war hero," Trump said at the 2015 Family Leadership Summit in Iowa. "He's a war hero because he was captured. I like people who weren't captured."

"I was heartbroken. I wish he would apologize. It's that simple. I just wish, I would implore him to apologize for it," Meghan McCain said. "I think it's dumb politics. And I think that maybe his ego's in the way or whatever. But I would implore him at this moment to apologize for it. ... I don't know if he's capable of apologizing."

She said that attacks on her father are even more hurtful now that he is battling a deadly form of brain cancer.

"[My father] really is the most resilient man in the world. He was fine when he was diagnosed. I mean, he was like, 'I fought tougher battles than this. We're going to hit this like we do everything else,'" she said. "I was a mess. My mother was very strong. My father was very strong. My siblings were very strong, and I was just a complete mess."

The emotional strain of her father's illness sometimes bubbles up on "The View" set.

When former Vice President Joe Biden stopped by the show, he comforted Meghan McCain as she talked about her father's cancer. Meghan McCain and Biden held hands and both started tearing up at one point.

Biden's son Beau Biden died in 2015 from the same cancer McCain's father is now battling. The Bidens and McCains have been friends for decades.

"I can reach out to him at any time, which is an incredible thing, resource to have, given that he is a very powerful, famous man," Meghan McCain said. "I don't bother him all the time, but I have cried to him on multiple occasions that weren't just on television and I am intensely grateful for him and his wife and his family. And I love them dearly and I think about Beau every single morning."

She said she initially wanted to turn down the job at "The View," but changed her mind after she spoke with her father.

"He was like, 'Are you crazy? Why wouldn't you take an amazing [opportunity]?' ... He was like angry that I was so dismissive about it," she said. "He watches every single day, and he does his physical therapy with his trainers and watches 'The View' to do it."

Her debut on the show was met with tabloid stories of cat fights with her co-hosts.

"Two weeks in, I was like, 'This is going great! Everything's amazing.' ... [Then] maybe one of the worst articles that's ever been written about me comes out about how everyone hates me here and I'm an ice princess," she said.

Meghan McCain said it was "unfair to pit women against each other."

"Men never get the same criticism and the same kind of articles, the catty, sexist, misogynistic B.S.," she said.

Meghan McCain said that no matter how big the disagreement gets among the co-hosts, there are no hard feelings on the set.

"I will say the women are really good at letting what happens on air, stay on air," she said.

Watch the full story on ABC News' "Nightline" TONIGHT at 12:35 a.m. ET.