Trump fumes as Mark Cuban supports Harris in his campaign.
Donald Trump lashed out at fellow billionaire Mark Cuban, who has been actively supporting his Democratic rival, Vice President Kamala Harris. AFP/GETTY IMAGES

Former President Donald Trump launched a fierce attack on billionaire Mark Cuban on Saturday, expressing his anger over Cuban's strong support for his Democratic opponent, Vice President Kamala Harris, in the ongoing campaign.

"Mark Cuban is a Loser," Trump wrote in post on Truth Social on Saturday. "Wouldn't take his phone calls anymore while at the White House, and he went rogue. A weak and pathetic 'bully,' he's got nothing going. Really low clubhead speed, a total non-athlete!"

Trump's insults were made just a few days after Cuban publicly mocked the tariff proposals put forth by the Republican presidential nominee at a rally supporting Vice President Harris. This exchange highlights the escalating tensions between the two billionaires in the context of the ongoing campaign.

On Friday, Cuban made an appearance on "Real Time With Bill Maher," where he took aim at the Republican presidential nominee's alarming rhetoric regarding the potential use of the military against political opponents. He remarked, "It's a new season of The Sopranos," expressing disbelief at the state of political discourse, calling it "crazy."

Cuban has been actively campaigning for Vice President Kamala Harris across multiple states, co-leading the initiative "Business Leaders For Harris" alongside LinkedIn founder Reid Hoffman. Just the day before, he joined Harris for a rally in Wisconsin, emphasizing his commitment to her campaign.

During his address in Green Bay, Cuban also directed a pointed jab at Trump, saying, "In my career, I've learned a lot about business, including how tariffs work. Now let me ask you a question: do any of you know someone who doesn't know how tariffs work? Here's a hint— that other guy," highlighting his criticism of Trump's understanding of tariff policies.

Trump has proposed implementing a 20% universal tariff on all imports, alongside an even higher 60% tariff on goods from China. This ambitious plan has faced significant backlash from economists, who caution that such a hardline approach would likely lead to increased costs for U.S. importers. Ultimately, they argue, these costs would be passed on to consumers, resulting in higher prices for everyday goods. Critics warn that the proposal could have negative implications for the overall economy, potentially leading to inflation and reduced purchasing power for American households.

In 2015, Cuban referred to Trump as "the best thing to happen to politics in a long time," yet he went on to support former Secretary of State Hillary Clinton in the 2016 election.

Since then, Cuban's once-friendly relationship with Trump has soured significantly. During this election cycle, he has taken on a prominent role as a surrogate for Harris's campaign, contributing to her image as a pro-growth capitalist.

Additionally, the former "Shark Tank" host seems to be eyeing a potential government role for himself, frequently hinting at the possibility of replacing Gary Gensler as the Chair of the Securities and Exchange Commission.

At the same time, Trump has enlisted Elon Musk as a prominent billionaire surrogate for his campaign, adding another layer to the rivalry with Cuban. This partnership not only highlights the differing alliances within the billionaire class but also underscores the contrasting political strategies as each seeks to rally influential figures to their side. As Musk lends his support to Trump, the competition between these wealthy figures becomes even more pronounced, setting the stage for an interesting dynamic in the upcoming election.