• Kamala Harris is campaigning for president against Elon Musk as much as she is against Donald Trump, Mark Cuban said.
• Cuban took a swipe at the Tesla and SpaceX CEO over his announcement of a $1 million per day swing-state voter sweepstakes, calling it "innovative" and "desperate."
• Musk, who is heavily funding a pro-Trump super PAC, has repeatedly mocked Cuban's looks.

Vice President Kamala Harris is campaigning for president against Elon Musk at least as much as she is against former President Donald Trump, Mark Cuban said Monday, as he advocated for the Democratic nominee as the pro-business choice.

"It's the Harris campaign versus Elon, not even versus Trump," the billionaire investor and former "Shark Tank" host said on CNBC's "Squawk Box."

Cuban took a swipe at the Tesla and SpaceX CEO over Musk's promise to give $1 million per day to the winner of a swing-state voter sweepstakes, calling it "innovative" and "desperate."

But Cuban later predicted that if Harris wins, she "100%" could mend her relationship with Musk.

Cuban's remarks were the latest volley between the two billionaires, who have taken on increasingly prominent campaign roles while ramping up attacks against each other.

Musk, who has contributed tens of millions of dollars to a pro-Trump super PAC, repeatedly mocked Cuban's looks, after Cuban said that few other CEOs are backing the GOP nominee.

Cuban shot back on Thursday: "You can't stop thinking about me @elonmusk Can you?"

"It's ok. I understand. If I supported a candidate that was so incompetent I had to take over and fund their ground game, I would be looking for a distraction too," Cuban added in the post on X, the social media platform Musk owns.

Cuban called out Musk again Monday morning on CNBC.

Asked for his view on the latest polls, which broadly show a neck-and-neck race between Harris and Trump, Cuban said, "Nobody really knows, and so really it comes down to get out the vote."

"And the crazy thing is, it's the Harris campaign versus Elon, not even versus Trump," said Cuban.

Musk, the world's richest man, has indeed emerged as one of the Trump campaign's most prominent surrogates, as well as one of the biggest spenders in the 2024 election. He has led get-out-the-vote efforts in the key swing state of Pennsylvania and given nearly $75 million to his America PAC between July and early September alone.

Trump now regularly boasts of having Musk's support, and has suggested that the CEO could take on a prominent role in his administration if he wins the election.

Musk, in turn, is embracing his status as one of Trump's top backers.

On Saturday, Musk said he would randomly give $1 million per day to registered voters who sign a petition for that PAC.

"It's innovative and it's desperate," Cuban said of that giveaway on CNBC. "You only do that because you think you have to."

Cuban conceded that a sweepstakes is "not a bad idea," but he wasn't convinced that it would work.

"It just as easily could backfire," he said, "but you don't know until you try."

Cuban went on to deliver a multipronged argument for Harris as a better presidential candidate for small businesses and the economy while contrasting her with Trump.

He said that Harris has promised not to raise taxes on Americans making $400,000 a year or less, which Cuban noted is a group that covers most small-business owners.

Cuban, the founder of Cost Plus Drugs, also pointed to Harris' focus on lowering health care and pharmaceutical prices by taking on pharmacy middlemen. He argued that those savings could offset inflation for households and small businesses.

"She has come out and talked about it. Donald Trump hasn't said a word."

He also argued that Harris' approach to addressing illegal immigration would be better for businesses than the mass-deportation plan put forward by Trump.

"I sat in front of restaurant owners and I asked, 'What would it be like if all of a sudden you've got a knock on your door and there was somebody from Stephen Miller squad asking you for the names and addresses and immigration status of everybody that works for you?'" Cuban said.

"That's not how you can run a country."

Cuban also repeated his criticisms of Trump's vow to use sweeping tariffs as a main tool of both his economic and foreign policy. Cuban said it was "insane" that Trump proposed using tariffs to deter a Chinese incursion into Taiwan.