Mark Cuban campaigns for Harris, infuriating Trump.

• Mark Cuban, a billionaire and staunch supporter of Vice President Kamala Harris, has been actively campaigning for her, drawing criticism from former President Donald Trump.
• Several days after Cuban mocked Trump's tariff proposals at a Harris campaign rally, Trump responded with insults.
• In 2015, Trump was praised by Cuban as the "best thing to happen to politics in a long time." However, their relationship has since soured, resulting in a sharp contrast between their animosity.

On Saturday, former President Donald Trump criticized billionaire Mark Cuban for supporting Vice President Kamala Harris's campaign.

"Trump wrote on Truth Social that Mark Cuban is a "Loser" and "a weak and pathetic 'bully' with no athletic skills." He also claimed that he stopped taking Cuban's phone calls while at the White House."

Several days after Cuban mocked Trump's tariff proposals at a Harris campaign rally, Trump responded with insults.

Cuban stated at a Harris rally in Wisconsin on Thursday that Trump has a limited understanding of tariffs, believing that China pays for them.

Trump's proposed tariffs on imports, including a 20% universal rate and a 60% rate for Chinese imports, have faced criticism from economists who argue that U.S. importers and consumers would bear the cost burden of such a hardline approach.

In 2015, Trump was praised by Cuban as the "best thing to happen to politics in a long time," in a "Fox & Friends" interview. However, their relationship has since soured, resulting in a stark contrast to their previous positive views of each other.

Trump in turn thanked him for the kind words.

In the 2016 election, former Secretary of State Hillary Clinton received Cuban's endorsement. Since then, their once-friendly relationship with Trump has become increasingly frosty.

During this election cycle, Vice President Harris has frequently appeared as a Cuban campaign surrogate, with the aim of positioning herself as a pro-growth capitalist.

The former host of "Shark Tank" has expressed interest in running for a government position, including replacing Securities and Exchange Commission Chair Gary Gensler.

Elon Musk has been appointed by Trump as his campaign surrogate, sparking a rivalry with Cuban.

"Cuban stated in a Friday interview on "Real Time With Bill Maher" that Musk could be one of the greatest entrepreneurs of the last century and still be a troll."