Billionaires go into battle at rival events for Harris and Trump

• X majority owner Musk has become a Republican mega-donor as he pushes for Trump's re-election, while Cuban is a prominent backer of Harris.
• And Axios' Dan Primack notes that with nearly nine million followers on X, Cuban is serving as a social media counterweight.

The big picture: At Harris' La Crosse, Wisconsin, event, Cuban took aim at Trump's proposal for tariffs, calling it "basically just gibberish," singling out the Republican presidential nominee's vow to place a 60% tariff on Chinese imports if he reclaims the White House as "crazy."

• "This man has so little understanding of tariffs, he thinks that China pays for that," the entrepreneur and "Shark Tank" star said.
• "This is the same guy who also thought that Mexico would pay for the wall," added Cuban in reference to the incomplete barrier at the southern border that Mexican officials ruled out paying for.

Meanwhile, Musk held his first solo event for Trump in Folsom, Pennsylvania, just outside of Philadelphia, after appearing with the Republican presidential nominee at his return to Butler, Penn., earlier this month.

• Musk likened the situation at the border in 2023 to "a zombie apocalypse" and said "it's not safe to walk around" U.S. cities.
• "If we get four more years of this," with Harris elected, "we're going to be fully in 'Mad Max,'" Musk added in reference to the dystopian action movie franchise.

• "Pennsylvania is, I think, the linchpin in this election, and this election, I think, is going to decide the fate of America and, along with the fate of America, the fate of Western civilization."

State of play: Immigration and the U.S.-Mexico border have emerged as key issues for voters this election.

• Border Patrol encounters with immigrants crossing from Mexico reached record highs in 2016, but numbers sharply dropped after the Biden administration launched harsh asylum restrictions.
• Trump has vowed to carry out the mass deportation of undocumented immigrants if re-elected, while Harris is also pledging to impose some of the most restrictive immigration, asylum and border policies in decades if she wins in November.

Go deeper: These celebrities have endorsed either Harris or Trump for president