NEW YORK (AP) — The windows of Eric Trump's office in the Trump Tower offer breathtaking views of some of Manhattan's most expensive real estate. It's there the youngest of Donald Trump's adult sons is reflecting on eye-opening moments from a world far away.

"Having to speak at a Pizza Ranch in Iowa, you hear things you never would," he says from the 25th floor office in Trump Tower, steps from the offices of siblings Ivanka and Don Jr. and one floor down from their father. "For us, the learning curve was exponential."

As his father's seemingly quixotic campaign caught fire, Eric Trump, 32, an admitted political neophyte, found himself thrust into the heart of it all. He barnstormed across small towns in Iowa and New Hampshire, gamely doing interviews on local radio stations and Fox News, all while balancing growing responsibilities to the company.

"The process makes you go out there and see this country," he says. "I knew nothing about the nuts and bolts of politics before this."

When Donald Trump announced his underdog candidacy for president last June, he empowered his three grown children to take the lead running the billion-dollar business that made him a worldwide celebrity.

Eric Trump says he and his siblings would relish the opportunity to prove themselves by taking over the empire completely if their father becomes president. If so, he says: "We'd always be one phone call away if he needs it. We'd do anything for the man. But our focus is this company. He's had to make politics his focus and he's shown confidence in us that we'll do a great job with the company."

Eric Trump estimated that at the start of his father's campaign, he spent just 10 percent of his time on the campaign and the rest on the business, overseeing projects like new hotels in Vancouver and Rio de Janeiro and a golf course in Scotland.

Now he's heavily invested in the campaign and that's expected to grow further. Those around the campaign say Eric, though at times overshadowed by his brother Don's seniority and his sister Ivanka's celebrity, has been tireless in providing advice and appearing on behalf of his father.

And all three children — whose mother is Ivana, Trump's first wife — are expected to do even more in the general election campaign, including pitching in to soften the rough edges of his public image.

Their love for their father — and apparent level-headedness, despite growing up among fabulous riches and bold-faced names — was prominently on display during a good-humored and affectionate appearance on CNN last month. Eric Trump said he is happy to act as a walking, talking testament to his dad in the likely showdown against Hillary Clinton, which would feature a pair of prominent and complicated families. "If I can be a character witness for him, and tell people about the man that he is, I want to do that," Eric said.

There have been some bumps in the road.

Eric and Ivanka Trump were the subject of some embarrassing headlines when it was revealed that they were not registered to vote in time for their father in last month's New York primary. An African big-game safari Eric and Don Jr. took drew criticism from animal rights activists. And an envelope filled with white powder was sent to Eric Trump's Manhattan home in March, though tests later revealed the substance was harmless.

And there have been moments when their father's divisive policies have conflicted with the family business. The furor over Trump's rhetoric about illegal immigrants and plans to build a Mexican border wall caused a celebrity restaurateur to back out of a hotel project in Washington, and a charity golf tournament was canceled after organizers feared it had become too political.

It remains to be seen how the Trump Organization would be run with Trump in the White House. His would be the largest business empire to belong to a sitting president, and that means a nest of ethical questions.

On the most basic level, federal ethics rules would not bar Trump from personally running his business interests from the White House, or — perhaps more likely — from having influence over decisions made by his children.

Eric — whose wife, Lara, works at the tabloid TV show "Inside Edition" and sports a Trump sticker on her smartphone case — insists that, if elected, his father would completely walk away from the family business, ensuring a "distinct separation" between the enterprise and public office.

"I think we're going to win this crazy thing," he said.

For now, Eric Trump's life is a juggling act. The day after the interview, he caught a flight to Ireland to open a Trump-branded golf course.