Donald Trump and Family Talk to Barbara Walters About His Presidential Run, What His Kids Think of Their Upbringing, and How He Is Handling the Role of Grandpa Trump

— -- Donald Trump seems to have it all. He’s expanded his real estate company into a multibillion-dollar Trump brand, had a long-running reality TV series and behind the scenes, he has a supportive family -- his three eldest children all work for his company, The Trump Organization.

But there is one thing he doesn’t have.

“The one thing that I want right now is the presidency because I don't want it for myself,” he told Barbara Walters. “I don't need it for myself, for my ego. I just think I'd do a great job.”

Donald Trump, his wife Melania and four of his children all sat down with Barbara Walters for an interview on ABC News’ “20/20” to talk about their family, home life, and how they feel about Trump’s run for the White House.

Here are some of the biggest highlights from Walters’ interview with the Trump family:

1. Donald Trump Considered Going to Film School

As a child, Trump said his first fantasy was to become a baseball player.

“Catcher, first base, but, you know, might have been able to do it but in those days you got paid $2, right?” he said, laughing.

But his other fantasy from growing up, he said, was that in high school and early college he thought he wanted to make movies.

“I was going to apply to the university -- to USC [University of Southern California], the movie school, which was one of the great movie schools and I decided not to,” he said. “I decided to go into the real estate business.”

2. Donald Trump Recalls When He Decided to Run for President

Trump has flirted with running for president multiple times over the years, but said the first time he seriously considered it was in 2012.

“The time I really thought about it [running for president] was last time when Mitt Romney ran, and he ran and I decided not to do it,” Trump told Walters. “I had a lot of obligations. I was-- signed a contract with ‘The Apprentice,’ and I had a lot of buildings under construction, I was doing a lot of things. It was sort of difficult to do it then.”

“Now, I’m perfect,” Trump continued. “It’s perfect, although I gave up two season of ‘The Apprentice’ to do it.”

3. Donald Trump Thinks of Himself as a 'Unifier'

“I am a nice person, but I think the thing that will surprise people, I’ll be a unifier,” he said. “I think I’ll bring people together, and that includes blacks and whites and everything. I think people will come together.”

4. Donald Trump on Immigration and Building a Wall on the US-Mexico Border

“We have to build a wall,” Trump told Walters. “We have to create a border. We have to have a wall. We’re going to have a wall. It’s going to be a real wall, not a little wall that they drive trucks with drugs over the top of it.”

“And it’s not going to be hard to build,” Trump added. “It’s got to be done, hey, who’s better at building than me? I know exactly what to do.”

Trump has come under fire for disparaging remarks he has made about immigrants. In his immigration reform plan he rolled out in August, Trump calls for the deportation of millions of undocumented workers in the U.S. and called for the end to birthright citizenship for the children of undocumented immigrants.

In his interview with Walters, Trump said when it comes to undocumented immigrants, he wants to deport the whole “family unit,” men, women and children.

“The people that are here legally, Hispanics, like me because they don’t want people coming in and taking their jobs,” he said.

When asked if he spoke Spanish, Trump said, “This is an English-speaking country, remember?”

Trump has also been very vocal about wanting to ban all Syrian refugees from coming into the U.S.

"We have no idea who the people are,” Trump said. They have no papers. They have no paperwork. You can get forged documents very easily in Syria… "We have no idea who they're letting into our country and our country has enough problems.”

5. Donald Trump on Going After ISIS

In the wake of the Paris attacks, France launched a series of airstrikes on ISIS targets in eastern Syria. The French Ministry of Defense announced it had dropped 20 bombs on ISIS’s de facto capital Raqqa just hours after the attacks.

The U.S., which launched a coalition against the Islamic State group in Iraq last year and expanded its campaign to Syria in September, also sent FBI agents to Paris to help with the terrorist investigation.

When asked if the U.S. should declare war on ISIS, Donald Trump said, “I think so.”

“Right now, we’re being so politically correct, nice and gentle, nice and gentle,” he said. “Right now they’re getting people who have this great respect for ISIS because ISIS is getting away with murder. They’re knocking out airplanes, they’re knocking out night clubs in Paris… you can’t let that happen.”

“You got to take them out swiftly and strongly,” he continued. “These people are crazy, OK? These people are crazy.”

If he were in the White House today, Trump said, “I would be saying, ‘Let’s go folks.’”

“I’m the most militaristic person,” he added. “I will make our military so strong and so powerful, nobody is going to mess with us.”

6. What Donald Trump Will Do If He Loses the Republican Nomination

If Trump doesn’t win the Republican nomination for president, he said he would go back to what he was doing before.

“Everyone says, ‘Oh you'll never lose.’ Look, you can always lose,” he told Walters. “You're going against people that are senators and governors, they're not stupid people. You can lose the nomination, you can lose the election. What's next? I go back to what I doing.”

“I loved what I was doing,” he added. “I love doing it. To be honest with you. I've built a great company, but this [the presidency] is just a greater calling… But I think this is just a greater calling I mean, this is the ultimate calling.”

7. Donald and Melania Trump on Their Marriage

Melania Trump was born in Slovenia when it was still part of Yugoslavia. She went to university to study architecture when she was discovered at age 17 by a major fashion photographer and moved to New York City.

It was at a New York Fashion Week party in 1998 that she met Donald Trump.

“He was very charming and… we had a great sparkle,” Melania told Walters. “He came with a date, so he asked me for the number and I said… ‘I will not give you my number, so if you give me your numbers I will call you.’”

“He was known as kind of a lady’s man,” she continued, laughing. “But, we had great chemistry the first time.”

“We’ve had great chemistry ever since,” added Donald Trump.

When they got married in 2005, Melania was Trump’s third wife and he already had four children from two previous marriages. His first wife was Ivana Zelnickova until the couple divorced in 1992, and then he married actress Marla Maples a year later. They called it quits in 1999.

Now having been married to Melania for 10 years, Donald Trump said what makes this marriage different for him is the benefit of time.

“I’ve gone through tremendous amounts of everything, deals and building companies and taking care of people,” he told Walters. “It hurts a marriage because you’re working all the time… what I did is I worked so hard that I think it was a very, very hard thing for somebody to compete with.”

Melania said she didn’t have any concerns about her husband being married twice before.

“We have great chemistry,” she said. “To be with a man as my husband is—you need to know who you are… you need to have a very independent life as well and supporting him, you need to be very smart and quick, and be there for him when he needs you.”

Melania said she has been absent from the campaign trail so she can stay home with her and Donald’s son, 9-year-old Barron, and admits Donald being away on the campaign trail has been tough.

“When he comes home we spend time together, two of us, or two of us and Barron, and-- just spending home and be at home, because that's a really quality time together,” she said.

8. Melania Trump on What Kind of First Lady She Would Be

If Donald Trump wins the presidency, Melania Trump will be the first foreign-born First Lady since John Quincy Adams wife, Louisa, and she would be the first to have posed in revealing photos for magazines like Sports Illustrated.

But Melania said she doesn’t believe her past modeling career is a liability to her husband’s image.

“I think people will always judge, and maybe they will say, ‘Oh, the past that you have, the way you were modeling,’ That’s part of the job that I was doing,” Melania told Walters. “I was a very successful model and I did some photo shoots.”

“If I’m lucky enough to win… the public will be so lucky to Melania as the First Lady,” Trump added. “She will be so beautiful and elegant and good from the heart.”

When asked what sort of causes she would take up as First Lady, Melania said she is already involved in “many, many charities.”

“Many different charities involving children, involving many different disasters,” she said. “If the time comes I will choose what is dearest to my heart.”

9. Donald Trump’s Children on What He Taught Them About Privilege

Four of Donald Trump’s five children, Donald Jr., Ivanka, Eric and Tiffany Trump, talked with Barbara Walters about what they see in the man they all call Dad. Trump’s youngest, his 9-year-old son Barron with Melania Trump, did not attend the interview because he was at school.

The four eldest all said that their father had pushed them to work hard since they were little.

“We refer to it as ‘The Trump Guilt,’ when we wake up on Saturday and we're not working,” Donald Jr., 37, said, laughing. “To say we weren't spoiled would be laughable, but we were spoiled with great education, great experiences.”

“We weren't the kids showing up to college with, you know, a Ferrari. That was not the way we were brought up,” he continued. “We always had to sort of earn whatever it is that we wanted. And that drive, I think, prevented us from doing a lot of the other things that you've seen as, you know, downfalls, perhaps, in other children who have similar circumstances.”

Ivanka, 34, agreed and said their father had taught them “since birth” that they “were lucky to have been afforded” such a luxurious lifestyle.

“He was the first to tell us how privileged we are. And with that privilege how much responsibility we had to really sort of earn,” she said.

“Well, that's the right word ,’earn,’ added Eric Trump, 31. “I mean, he made us work. … we were on construction sites, and we were working, and at the end of the day, you were tired, and you earned minimum wage, and you'd take that money that you had and you'd go out and spend it on something good.”

10. The One Thing Donald Trump’s Kids Say Their Dad Needs to Work On

Trump’s children have long said they are his biggest cheerleaders. Although their dad has been criticized for the remarks he has made about immigrants, women, including commenting on GOP rival Carly Fiorina’s looks, Trump’s children say there is nothing their father has said on the campaign trail or at the GOP debates that have bothered them.

“He's not a big believer in P.C. culture where every statement you make you have to vet very carefully through thousands of people,” Donald Jr. said. “But if people really break down what he's trying to say, there's no malice in there. He's just cutting through the nonsense and getting to the point and not wasting time. That's what he does.”

“He's true to himself,” added Tiffany Trump, 22. “And he speaks in a way that the average person can understand. I think that's refreshing for everyone.”

The only thing Ivanka and Donald Jr., would say is that their dad loves McDonald’s and they wished he would eat healthier and maybe slow down.

“Sometimes I tell him, like, ‘Oh, you have to, you know, slow down,’” Ivanka said. “But it’s the only speed he knows, and I kind of love that about him.”

11. What Donald Trump’s Children Think of Him as a Grandfather

Donald Trump has seven grandchildren, ranging in age from 8 years old to 17 months, with one on the way.

Donald Jr., who was married in 2005, has five kids of his own, while Ivanka, who was married in 2009, has two children and is pregnant with her third, and both said Grandpa Trump has been great with the little kids.

“He's at a different stage in his life,” Donald Jr., said of his dad. “He's able to relax a little bit more and be a grandfather. I can see my kids just running up to him and giving a hug… They just respect him a lot.”

Ivanka joked that her children already have started to take after their grandfather.

“A few months ago… we're walking down the street, and my daughter sees a large pot hole in the middle of a New York City street… And she goes, ‘Mom, Grandpa would not like that,’” Ivanka said. “So it's very cute… and she's 4. So she's observed him.”

Donald Jr., said his youngest sibling, 9-year-old Barron, has also bonded with his children.

“He's very close to my 8-year-old and my almost 7-year-old,” Donald Jr., said. “They have a great relationship. So it's almost-- we joke, ‘you have to really respect your uncle,’ even though there's a one year difference,” so that drives my kids crazy… But they play almost as though they're, you know, cousins or brothers and sisters.”