Yesterday, Elon Musk, CEO of SpaceX and Tesla and the richest man in the world, tweeted that Federal Trade Commission chair Lina Khan “will be fired soon.” Musk is hardly the only billionaire upset by Khan’s aggressive use of antitrust law to limit the power of big corporations — and, hence, to limit the power of billionaires like Musk. Mark Cuban, the billionaire surrogate for the Harris campaign, has also said Khan must go. So have major Democratic donors like Reid Hoffman and Barry Diller. When a bipartisan group of billionaires agree that a government official who’s limiting their power mu…