Mark Harris

TrumpRx is in partnership with Mark Cuban's company Cost Plus Drugs.

Mark Cuban has been a harsh critic of Donald Trump in the past.

Trump joked Cuban's endorsement for Kamala Harris was a 'big mistake.'

Billionaire Mark Cuban joined President Donald Trump at a May 18 event on drug prices.

The Trump administration announced the expansion of TrumpRx.gov, a government website listing discounted prescription drugs negotiated by his administration. The website will refer people to private-sector online pharmacies and drug-pricing websites, including Cuban's Cost Plus Drugs, Amazon Pharmacy, and GoodRx.

"Republicans want cheaper drugs. Independents want cheaper drugs. Democrats want cheaper drugs," Cuban said at the event. "I think we're going to do something special."

Cuban's partnership with Trump may have raised eyebrows for some people, since the former "Shark Tank" star and owner of the Dallas Mavericks endorsed Trump's opponent, former Vice President Kamala Harris.

Mark Cuban had harsh words for Donald Trump

Cuban recalled having a falling out with Trump as he was making his first run for president. CBS News reported in 2016 Cuban was escalating his criticism of Trump, saying the then-presumptive nominee was getting "stupider" before his eyes.

"I was supporting him. Because again, I didn't think he would win. And then as I started talking to him more about things, I asked him questions about real estate and he didn't really understand the financial side of real estate," Cuban said on the "Just B with Bethenny Frankel" podcast in 2020. "It was just clear he wasn't somebody who learned about anything. That's where we kind of had our falling out."

Cuban also said Trump was the first person to tell him that he should run for president himself. He said he considered running as an independent candidate but decided against it based on pollster projections of a race against Trump and former President Joe Biden.

"Look, personally I don't have a problem with the guy," Cuban said on the podcast. "Now professionally as the president, I think he's an idiot. You know, I never thought he was smart in talking to him."

The Trump Twitter Archive shows Trump was critical of Cuban even before the 2016 election.

"I know Mark Cuban well. He backed me big-time but I wasn't interested in taking all of his calls. He's not smart enough to run for president!" Trump wrote in February 2017.

Mark Cuban said he wouldn't endorse Kamala Harris again

Cuban endorsed Harris in the 2024 presidential election, which Trump at the May 18 event called a "big mistake."

In one viral comment in the election, Cuban said Trump is never seen around "strong, intelligent women" because they intimidate him while speaking on ABC’s “The View.” He clarified the comments on X, saying he was talking about former South Carolina Gov. Nikki Haley not being active in his campaign.

"I stand by my opinion that he does not like being challenged publicly," Cuban concluded.

Since Trump took office, Cuban has been critical of the Democrats for their messaging.

“It’s just, ‘Trump sucks.’ That’s the underlying thought of everything the Democrats do. ‘Trump sucks.’ Trump says, ‘The sky is blue’: ‘Trump sucks,’” he said on Crooked Media’s “Pod Save America" in July 2025, according to The Hill. “That’s not the way to win. It’s just not.”

Cuban said firmly at POLITICO’s Health Care Summit in April he would not like to see Harris run for office again. He praised Trump's efforts to bring the drug prices down.

Talking to reporters after the May 18 event, Cuban declined a question about supporting Harris, saying "I'm not talking about my politics at all," according to Fox News' "Outkick."

Contributing: Ken Alltucker, Scott Gleeson, USA TODAY