Donald Trump lashed out at former ally Mark Cuban on Saturday. “Mark Cuban is a Loser. Wouldn’t take his phone calls anymore while at the White House, and he went rogue,” Trump wrote on Truth Social. “A weak and pathetic ‘bully,’ he’s got nothing going.” But he capped off the run of insults by attacking something Trump truly values: his target’s golf game, just like he did while debating Joe Biden earlier this year. “Really low clubhead speed, a total non-athlete!”

While speaking at a rally held in support of Kamala Harris on Thursday, Cuban slammed Trump’s understanding of business. “I’ve learned a lot about business, including how tariffs work,” Cuban said. Trump appears to “thinks that China pays for them,” adding, “This is same guy that thought that Mexico would pay for the wall.”

With the post, Trump included a clip of vocal supporter and yet another fellow billionaire Elon Musk speaking at a campaign event in support of Trump on Friday. Musk inserted himself into the conversation about Cuban, telling attendees, “I saw an interview with Mark Cuban and, what’s-her-name again, Rachel Maddow… but I couldn’t tell which was which.”

Cuban spoke to Maddow on Tuesday about his past dealings with Trump. The pair initially got along well — in 2015, Cuban contemplated being Trump’s vice president during his first presidential campaign. But the relationship soured after Cuban “fairly quickly realized that Trump was was very much not the best thing to happen to politics, and it’s been a very long time since he said anything nice about Trump and his political prospects,” Maddow said.

Cuban had no plan to break that streak Tuesday night. He told Maddow, “There’s really no good reason to vote for Donald Trump as the business candidate” and added, “You know, in doing business, whether you’re a small company or very large company, you want stability. You don’t want to wake up one morning as the CEO of John Deere and find out all of the sudden you’ve got a 200% tariff.”

Trump has repeatedly vocalized support for tariffs that could top 60% on goods imported from China. He has argued that the higher import tax will bring increased revenue to the United States and allow him to cut tax rates without inflation rising. The plan has been panned and described as “dangerous.”

Apparently offended by Cuban’s continued criticism of him and praise for Harris, Trump also shared a link to a Fox News article from August about a poll Cuban conducted among his followers on X. Cuban asked, “Whose persona and character would you like to see young children grow up to have?” Trump won the poll 68.9% to 31.2% on the Musk-owned platform.