On a brisk Friday evening earlier this month, David Sacks and Elon Musk convened a dozen or so of America’s most powerful business leaders for dinner at Sacks’ $23 million, 11,000-square-foot home in the Hollywood Hills. The dinner party, according to people familiar with the intimate gathering, comprised a veritable living room Milken conference: Michael Milken himself was there, in fact, as were billionaires Rupert Murdoch and Peter Thiel. A few government types, including Steven Mnuchin, scored invites. There were also some less politically active titans of industry, such as Uber co-founder and former C.E.O. Travis Kalanick. But all were there as members of a burgeoning anti-Biden brain trust, united by a shared sense of grievance.

The get-together, which hasn’t been previously reported, is the latest evidence of Musk’s growing power beyond Silicon Valley, as he’s evolved from political hobbyist to media owner and conservative icon. As I wrote last week, Musk has told associates that he’s interested in formalizing his running political commentary on Twitter/X into an official endorsement of some sort—either a statement against President Biden, or even something supporting Donald Trump. He has been encouraged to go deeper into politics this cycle by his friends Joe Lonsdale, the venture capitalist, and Steve Wynn, the casino magnate and Trump emissary. Both in public and in private, Musk has expressed feeling deeply unnerved by America’s migrant crisis—a fear that has driven his rush into Republican politics—and the issue was a key topic of discussion at the dinner. (Spokespeople for Musk, Sacks, and the other attendees either declined to comment or didn’t respond.)