The Las Vegas magnate who has been Donald J. Trump’s friend and business partner for two decades, told delegates at the Republican National Convention in Cleveland Wednesday that Trump’s vision and determination to succeed in business are the skills he needs as president to “Make America Great Again.”

Phil Ruffin, himself a billionaire and the owner of Las Vegas’s Treasure Island hotel, said Trump’s word is his bond. “If Donald tells you something, you can put it in the bank. He’s been my partner and friend–and believe me, his handshake is better than any contract you will ever write.”

It is unfair to denigrate his integrity, he said.

“He pays his bills promptly,” said the developer, who also owns the country’s largest maker of hand trucks. “You won’t hear that: promptly. No discounts.”

The Texas-born billionaire said Trump makes money and puts thousands of people to work in good-paying jobs because he sees opportunities other smiss.

“We were in New York, Park Avenue and 58th, there was a building called the GE Building. I didn’t like it, I said: ‘Donald, stay away from it,'” he said. “He bought it and made two or three hundred million dollars on the deal. That’s what he does. We’re in Palm Beach with Robert Kraft. Donald had a house on the ocean. He paid $40 million for it. I didn’t like it. I thought it was a mess. He sold it for $100 million. Shows you what I know.”

Ruffin is the half-owner of the Trump International Hotel and Tower, which was a project that almost went upside down when the real estate market crashed, leaving people unable to complete their purchase commitments, he said. “A beautiful hotel, all the Trump amenities–he knows how to build them with detail–we had almost 1,300 units and they were sold out in 90 days. That was in 2007, but in 2008, nobody could close. The recession hit. The banks shut down, so here we were stuck with 75 percent, only 300 units sold. We had $500 million in debt. What do you do?”

Trump does not give up, Ruffin said.

“He said let’s go forward with this project,” he said. “‘We’ll put the money in and we will make the damn-thing work’ and he did. By the way, we put in $30 million in four years. He didn’t squawk–he wired the money in.”

Today, the project is 80 percent sold and all the project’s debt is paid off, he said.

Ruffin added, “We’re gonna make a huge amount of money on it. It’s going to be a huge success.”

In a convention chock full of firsts, Ruffin’s review of the inner workings of one of Trump’s business deals had to be another. But, in a way it was in keeping with the intimacy people feel with Trump. He is a man, who has been in the news for more than 30 years. The only comparison would be John F. Kennedy, who because of his father, Ambassador Joseph P. Kennedy Sr., grew up in the newspapers with his family’s successes and tragedies played out on the front page for the more than 20 years before he was elected to the White House.

Americans all know the basic outlines of Trump’s story, but at this convention the campaign has brought forward speakers, like Ruffin, to color inside the lines. At the 2012 Republican National Convention, an army of consultants exhausted every trick in the black arts to convince America that Mitt Romney was not just humane, but a human. When Romney’s business partners spoke to America, they never dug deeper than the descriptions of the deals on the brochures. They were afraid to admit something might have gone wrong or that Romney ever made a mistake.

At the 2016 edition of this political drama, we have another kind of businessman. The man Ruffin described was a man who took risks and when things turned the wrong way was committed to getting things back on track.

“I believe in him. I’ve always believed in him,” he said. “I believe he’s tough. He’s smart. He knows what he’s doing.”

When he is president, he will not think about himself, he will put his skills, gifts, and insight to the service of America, he said.