The Moment Donald Trump, Family Knew He Won the Election

As the Trump family watched the results come in on election night at Trump Tower in New York City, Eric Trump's wife said there was a moment when she realized Donald Trump was going to win the presidency.

"My moment of Zen briefly was when we won North Carolina," Lara Trump told ABC News' "20/20," which is her home state.

But Trump said her father-in-law didn't want to believe it just yet.

"He didn't want it to be said until we knew, because he said, 'Don't tell me that if we haven't really won yet. I want to know for sure,'" she said.

Then the votes from Pennsylvania started coming in and it became more real to the family that Donald Trump was going to win.

"We were all elated and felt vindicated and so happy," Lara Trump said. "Everybody kept coming up and saying, 'We think we have Pennsylvania. We have it. You're going to win, you're going to be the next president,' and he said, 'I don't want to know until it's real, until someone has made it official.'"

But that's when Donald Trump immediately went to work on writing a speech, Lara Trump said, because he had written neither a victory nor concession speech until that point.

"He's a little superstitious," she said. "And I don't blame him."

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Donald Trump pulled off a stunning upset Tuesday night, beating former Secretary of State Hillary Clinton after grabbing key battleground states and several traditionally Democratic strongholds. Clinton called him to concede early Wednesday morning.

The victory for Trump, a billionaire real estate mogul with no political or military experience, over Clinton who has spent decades in public service, stunned observers and ran contrary to late polling, which showed Clinton with a slight lead going into Election Day.

When asked if she thought at the start of the campaign that Donald Trump would make it this far, Lara Trump said, "I would be lying if I gave him a 100 percent chance to get him into the White House."

"I think we were all surprised early on, actually, by the number of people that got behind him," she continued. "But I'll tell you I did switch my tune because as soon as I got out and started campaigning hard ... I really saw the movement that formed behind him behind him and the enthusiasm of the people."

The three eldest Trump children hit the campaign trail off and on throughout the election to stump for their father. Lara Trump was instrumental in organizing the "Women for Trump" slogan used on pink shirts, jackets and signs.

"I gave him [Donald Trump] a lot of credit for saying, 'Get out and do it,' because it's a very big deal to put that much faith in somebody," she said.

In the hours and days since Trump won, protests have sprung up across the country, including in New York City. The city stationed sanitation trucks filled with sand along the outside of Trump Tower to prevent anyone from ramming a vehicle into the building. Lara Trump said she watched as protesters marched up the street to Trump Tower.

"I really think that if people would just give him a chance they're going to see such an incredible president," she said.

Lara Trump said she and her husband Eric Trump don't plan to move to Washington, D.C., but instead will stay in New York so that Eric can continue to help manage The Trump Organization with his older siblings, Donald Trump Jr., and Ivanka Trump. All three are executive vice presidents of development and acquisition for the organization. But, she said, the prospect of Eric advising his father in the White House isn't out of the question.

"I think if he asks Eric to do almost anything he would do it," Lara Trump said. "So I guess the possibility is there."

ABC's John Santucci, Meghan Keneally and Maggie Hopf Kreer contributed to this report.