Mark Cuban tells 'All-In' podcast that the advice he tried giving Trump went unheeded

• Mark Cuban told the "All-In" podcast hosts that he used to talk to former President Donald Trump a lot.
• During Trump's 2016 campaign, Cuban said he tried to give some advice, but it went unheeded.

Mark Cuban wasn't always a never-Trumper.

In an interview on the "All-In" podcast that was published Thursday, Cuban said he was excited to see then-candidate Donald Trump, once an outsider candidate, run for president in 2015.

What soured the billionaire on Trump is that, according to Cuban, the former president never listened.

Cuban said during the podcast episode that he was once enthusiastic about the prospect of an outsider running for office.

"Alright, this guy's got no chance to win, but I think it's great because I don't like traditional politicians," Cuban said, recalling the time he saw Trump go down the golden escalators in June 2015. "There's nothing about me that thinks that the way we do politics or the way the government is run is a good thing. Not at all."

During the early stages of Trump's campaign, Cuban told the podcast hosts that he talked to Trump a lot, estimating about 10 to 15 times on the phone, and would try to give advice or talk shop on policy.

A spokesperson for the Trump campaign did not immediately respond to a request for comment from Business Insider.

But Cuban felt those conversations didn't go anywhere.

"I remember asking him, 'You know, you realize as president you're going to have to make decisions where people can die?'" Cuban recalled. "And he really wouldn't respond: 'Yeah, I get it, I get it.'"

Cuban told the podcast hosts that he would ask Trump about his campaign's ground game, and Cuban said Trump would brush off concerns: "Yeah, I got the evangelicals doing all that, I'm not worried about it."

Cuban also recalled a time when he tried to engage Trump in a discussion about privacy concerns.

He "just didn't want to talk about that at all," Cuban said, "and that would happen multiple times, where I would try to engage in conversations about some type of policy, and it never got anywhere."

One of the final straws, according to Cuban, was when he emailed Trump, "At some point you have to learn these things, you literally have to learn these things in order to be president, and he didn't respond."

Cuban said in the podcast that that's when he went on CNN in 2016 and told the outlet that Trump doesn't make an effort to learn.

"Look, I like the guy, but he's not learning," Cuban recalled telling CNN. "He doesn't make any effort to learn anything, and I think that carries on 'till this day because you can't look at the things he says and say, 'That's really an in-depth response.' Or, 'That's a nuanced response.'"

Cuban did not respond to a request for comment.

Cuban has been outspoken about his gripes against Trump, calling the former president "unethical" and criticizing him for turning the Republican Party into his "family business."

Even though the billionaire likes to emphasize that he's not a Democrat or a Republican, Cuban endorsed Vice President Kamala Harris shortly after President Joe Biden dropped out of the race in July.

"I've said this many, many times: If it was a non-MAGA candidate, particularly if it was Joe Biden still, I'd vote Republican," he told the podcast hosts. "I've voted Republican before."