Elon Musk and entrepreneur and investor David Sacks reportedly held a secret billionaire dinner party in Hollywood last month. Its purpose: to defeat Joe Biden and reinstall Donald Trump in the White House. The guest list included Peter Thiel, Rupert Murdoch, Michael Milken, Travis Kalanick, and Steven Mnuchin, Trump’s Treasury secretary. Meanwhile, Musk is turning up the volume and frequency of his anti-Biden harangues on his X platform. Since January, Musk has posted about Biden at least seven times a month, attacking the president for everything from his age to his policies on immigration a…